Common Weakness Enumeration

CWE-113

Allowed

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

Abstraction: Variant · Status: Incomplete

The product receives data from an HTTP agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes CR and LF characters before the data is included in outgoing HTTP headers.

191 vulnerabilities reference this CWE, most recent first.

GHSA-M9G3-3G99-MHPX

Vulnerability from github – Published: 2026-05-08 20:49 – Updated: 2026-06-08 23:29
VLAI
Summary
eventsource-encoder vulnerable to SSE event injection via unsanitized `event` and `id` fields
Details

Summary

eventsource-encoder does not sanitize the event or id fields of an EventSourceMessage before serializing them. An attacker who controls either field can inject arbitrary Server-Sent Events line terminators (\n, \r, or \r\n) and thereby forge additional SSE fields or entire messages on the stream. This is similar in spirit to GHSA-4hxc-9384-m385 (h3), but the vulnerable fields are event/id rather than data/comment. These are less likely to be user-controllable, but should still be sanitized.

Details

In src/encode.ts, encodeMessage interpolates event and id into the output without inspecting them for line terminators:

if (message.event) {
  output += `event: ${message.event}\n`
}
// ...
if (typeof message.id === 'string' || typeof message.id === 'number') {
  output += `id: ${message.id}\n`
}

The SSE specification treats \r, \n, and \r\n as line terminators. A \n (or \r) embedded in either field is rendered as the end of that field, allowing the rest of the input to be interpreted by the client as new SSE fields.

By contrast, data and comment already normalize all three line-terminator forms via NEWLINES_RE = /(\r\n|\r|\n)/g, so they are not affected.

Proof of concept

import {encode} from 'eventsource-encoder'

// Attacker-controlled value flows into `event`
const userSuppliedTopic = 'message\nevent: admin\ndata: {"role":"admin"}'

console.log(encode({event: userSuppliedTopic, data: 'hello'}))

Output:

event: message
event: admin
data: {"role":"admin"}
data: hello

The browser sees two events: a forged admin event with attacker-chosen payload, followed by the legitimate message event. The same primitive works through id for any string id value.

Impact

If untrusted input is passed into the event or id field of a message, an attacker can:

  • Spoof events of arbitrary type (rerouting payloads to handlers the attacker chooses)
  • Inject additional SSE fields (data:, id:, retry:) into the stream
  • Split a single encode() call into multiple distinct browser events
  • Override the client's Last-Event-ID via injected id: lines

The vulnerability requires that an application places attacker-controlled data into event or id. Applications that only put trusted, statically-defined values into these fields are not affected.

Patches

Fixed in eventsource-encoder@1.0.2. The event and string id fields are now validated; any value containing \r or \n causes the encoder to throw a TypeError rather than emit a malformed stream.

Workarounds

If users cannot upgrade, validate or strip line terminators from any untrusted value before passing it to encode / encodeMessage:

function safeSingleLine(value) {
  if (/[\r\n]/.test(value)) throw new Error('SSE field must be single-line')
  return value
}

encode({event: safeSingleLine(topic), id: safeSingleLine(id), data})

Resources

  • Related advisory (different package, same class): https://github.com/advisories/GHSA-4hxc-9384-m385
  • SSE spec, line terminators: https://html.spec.whatwg.org/multipage/server-sent-events.html#parsing-an-event-stream

Credit

Discovered while reviewing in light of GHSA-4hxc-9384-m385.

Show details on source website

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 1.0.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "eventsource-encoder"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44214"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-93"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T20:49:40Z",
    "nvd_published_at": "2026-05-26T20:16:19Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\n\n`eventsource-encoder` does not sanitize the `event` or `id` fields of an `EventSourceMessage` before serializing them. An attacker who controls either field can inject arbitrary Server-Sent Events line terminators (`\\n`, `\\r`, or `\\r\\n`) and thereby forge additional SSE fields or entire messages on the stream. This is similar in spirit to [GHSA-4hxc-9384-m385](https://github.com/advisories/GHSA-4hxc-9384-m385) (h3), but the vulnerable fields are `event`/`id` rather than `data`/`comment`. These are less likely to be user-controllable, but should still be sanitized.\n\n### Details\n\nIn `src/encode.ts`, `encodeMessage` interpolates `event` and `id` into the output without inspecting them for line terminators:\n\n```ts\nif (message.event) {\n  output += `event: ${message.event}\\n`\n}\n// ...\nif (typeof message.id === \u0027string\u0027 || typeof message.id === \u0027number\u0027) {\n  output += `id: ${message.id}\\n`\n}\n```\n\nThe SSE specification treats `\\r`, `\\n`, and `\\r\\n` as line terminators. A `\\n` (or `\\r`) embedded in either field is rendered as the end of that field, allowing the rest of the input to be interpreted by the client as new SSE fields.\n\nBy contrast, `data` and `comment` already normalize all three line-terminator forms via `NEWLINES_RE = /(\\r\\n|\\r|\\n)/g`, so they are not affected.\n\n### Proof of concept\n\n```js\nimport {encode} from \u0027eventsource-encoder\u0027\n\n// Attacker-controlled value flows into `event`\nconst userSuppliedTopic = \u0027message\\nevent: admin\\ndata: {\"role\":\"admin\"}\u0027\n\nconsole.log(encode({event: userSuppliedTopic, data: \u0027hello\u0027}))\n```\n\nOutput:\n\n```\nevent: message\nevent: admin\ndata: {\"role\":\"admin\"}\ndata: hello\n\n```\n\nThe browser sees two events: a forged `admin` event with attacker-chosen payload, followed by the legitimate `message` event. The same primitive works through `id` for any string id value.\n\n### Impact\n\nIf untrusted input is passed into the `event` or `id` field of a message, an attacker can:\n\n- Spoof events of arbitrary type (rerouting payloads to handlers the attacker chooses)\n- Inject additional SSE fields (`data:`, `id:`, `retry:`) into the stream\n- Split a single `encode()` call into multiple distinct browser events\n- Override the client\u0027s `Last-Event-ID` via injected `id:` lines\n\nThe vulnerability requires that an application places attacker-controlled data into `event` or `id`. Applications that only put trusted, statically-defined values into these fields are not affected.\n\n### Patches\n\nFixed in `eventsource-encoder@1.0.2`. The `event` and string `id` fields are now validated; any value containing `\\r` or `\\n` causes the encoder to throw a `TypeError` rather than emit a malformed stream.\n\n### Workarounds\n\nIf users cannot upgrade, validate or strip line terminators from any untrusted value before passing it to `encode` / `encodeMessage`:\n\n```js\nfunction safeSingleLine(value) {\n  if (/[\\r\\n]/.test(value)) throw new Error(\u0027SSE field must be single-line\u0027)\n  return value\n}\n\nencode({event: safeSingleLine(topic), id: safeSingleLine(id), data})\n```\n\n### Resources\n\n- Related advisory (different package, same class): https://github.com/advisories/GHSA-4hxc-9384-m385\n- SSE spec, line terminators: https://html.spec.whatwg.org/multipage/server-sent-events.html#parsing-an-event-stream\n\n### Credit\n\nDiscovered while reviewing in light of GHSA-4hxc-9384-m385.",
  "id": "GHSA-m9g3-3g99-mhpx",
  "modified": "2026-06-08T23:29:22Z",
  "published": "2026-05-08T20:49:40Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/rexxars/eventsource-encoder/security/advisories/GHSA-m9g3-3g99-mhpx"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44214"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/rexxars/eventsource-encoder"
    },
    {
      "type": "WEB",
      "url": "https://html.spec.whatwg.org/multipage/server-sent-events.html#parsing-an-event-stream"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "eventsource-encoder vulnerable to SSE event injection via unsanitized `event` and `id` fields"
}

GHSA-MFRC-633M-GCWG

Vulnerability from github – Published: 2022-05-14 01:35 – Updated: 2022-05-14 01:35
VLAI
Details

CRLF injection vulnerability in the HTTPConnection.putheader function in urllib2 and urllib in CPython (aka Python) before 2.7.10 and 3.x before 3.4.4 allows remote attackers to inject arbitrary HTTP headers via CRLF sequences in a URL.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2016-5699"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2016-09-02T14:59:00Z",
    "severity": "MODERATE"
  },
  "details": "CRLF injection vulnerability in the HTTPConnection.putheader function in urllib2 and urllib in CPython (aka Python) before 2.7.10 and 3.x before 3.4.4 allows remote attackers to inject arbitrary HTTP headers via CRLF sequences in a URL.",
  "id": "GHSA-mfrc-633m-gcwg",
  "modified": "2022-05-14T01:35:21Z",
  "published": "2022-05-14T01:35:21Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2016-5699"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2016:1626"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2016:1627"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2016:1628"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2016:1629"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2016:1630"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2016-5699"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1303699"
    },
    {
      "type": "WEB",
      "url": "https://docs.python.org/3.4/whatsnew/changelog.html#python-3-4-4"
    },
    {
      "type": "WEB",
      "url": "https://hg.python.org/cpython/raw-file/v2.7.10/Misc/NEWS"
    },
    {
      "type": "WEB",
      "url": "https://hg.python.org/cpython/rev/1c45047c5102"
    },
    {
      "type": "WEB",
      "url": "https://hg.python.org/cpython/rev/bf3e1c9b80e9"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2019/02/msg00011.html"
    },
    {
      "type": "WEB",
      "url": "http://blog.blindspotsecurity.com/2016/06/advisory-http-header-injection-in.html"
    },
    {
      "type": "WEB",
      "url": "http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html"
    },
    {
      "type": "WEB",
      "url": "http://rhn.redhat.com/errata/RHSA-2016-1626.html"
    },
    {
      "type": "WEB",
      "url": "http://rhn.redhat.com/errata/RHSA-2016-1627.html"
    },
    {
      "type": "WEB",
      "url": "http://rhn.redhat.com/errata/RHSA-2016-1628.html"
    },
    {
      "type": "WEB",
      "url": "http://rhn.redhat.com/errata/RHSA-2016-1629.html"
    },
    {
      "type": "WEB",
      "url": "http://rhn.redhat.com/errata/RHSA-2016-1630.html"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2016/06/14/7"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2016/06/15/12"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2016/06/16/2"
    },
    {
      "type": "WEB",
      "url": "http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html"
    },
    {
      "type": "WEB",
      "url": "http://www.securityfocus.com/bid/91226"
    },
    {
      "type": "WEB",
      "url": "http://www.splunk.com/view/SP-CAAAPSV"
    },
    {
      "type": "WEB",
      "url": "http://www.splunk.com/view/SP-CAAAPUE"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-MQH5-C2WX-V3PQ

Vulnerability from github – Published: 2025-01-21 18:31 – Updated: 2025-01-21 18:31
VLAI
Details

Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting') vulnerability in Payara Platform Payara Server (Grizzly, REST Management Interface modules), Payara Platform Payara Micro (Grizzly modules) allows Manipulating State, Identity Spoofing.This issue affects Payara Server: from 4.1.151 through 4.1.2.191.51, from 5.20.0 through 5.70.0, from 5.2020.2 through 5.2022.5, from 6.2022.1 through 6.2024.12, from 6.0.0 through 6.21.0; Payara Micro: from 4.1.152 through 4.1.2.191.51, from 5.20.0 through 5.70.0, from 5.2020.2 through 5.2022.5, from 6.2022.1 through 6.2024.12, from 6.0.0 through 6.21.0.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-45687"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-01-21T17:15:14Z",
    "severity": "LOW"
  },
  "details": "Improper Neutralization of CRLF Sequences in HTTP Headers (\u0027HTTP Request/Response Splitting\u0027) vulnerability in Payara Platform Payara Server (Grizzly, REST Management Interface modules), Payara Platform Payara Micro (Grizzly modules) allows Manipulating State, Identity Spoofing.This issue affects Payara Server: from 4.1.151 through 4.1.2.191.51, from 5.20.0 through 5.70.0, from 5.2020.2 through 5.2022.5, from 6.2022.1 through 6.2024.12, from 6.0.0 through 6.21.0; Payara Micro: from 4.1.152 through 4.1.2.191.51, from 5.20.0 through 5.70.0, from 5.2020.2 through 5.2022.5, from 6.2022.1 through 6.2024.12, from 6.0.0 through 6.21.0.",
  "id": "GHSA-mqh5-c2wx-v3pq",
  "modified": "2025-01-21T18:31:07Z",
  "published": "2025-01-21T18:31:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-45687"
    },
    {
      "type": "WEB",
      "url": "https://docs.payara.fish/community/docs/6.2025.1/Release%20Notes/Release%20Notes%206.2025.1.html"
    },
    {
      "type": "WEB",
      "url": "https://docs.payara.fish/enterprise/docs/5.71.0/Release%20Notes/Release%20Notes%205.71.0.html"
    },
    {
      "type": "WEB",
      "url": "https://docs.payara.fish/enterprise/docs/Release%20Notes/Release%20Notes%206.22.0.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

GHSA-MWCJ-9FQH-RC64

Vulnerability from github – Published: 2022-05-14 02:03 – Updated: 2022-05-14 02:03
VLAI
Details

Monstra CMS V3.0.4 allows HTTP header injection in the plugins/captcha/crypt/cryptographp.php cfg parameter, a related issue to CVE-2012-2943.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2018-16979"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2018-09-12T23:29:00Z",
    "severity": "MODERATE"
  },
  "details": "Monstra CMS V3.0.4 allows HTTP header injection in the plugins/captcha/crypt/cryptographp.php cfg parameter, a related issue to CVE-2012-2943.",
  "id": "GHSA-mwcj-9fqh-rc64",
  "modified": "2022-05-14T02:03:03Z",
  "published": "2022-05-14T02:03:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-16979"
    },
    {
      "type": "WEB",
      "url": "https://github.com/howchen/howchen/issues/4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

GHSA-MWH4-6H8G-PG8W

Vulnerability from github – Published: 2026-04-01 21:48 – Updated: 2026-04-01 21:48
VLAI
Summary
AIOHTTP has HTTP response splitting via \r in reason phrase
Details

Summary

An attacker who controls the reason parameter when creating a Response may be able to inject extra headers or similar exploits.

Impact

In the unlikely situation that an application allows untrusted data to be used in the response's reason parameter, then an attacker could manipulate the response to send something different from what the developer intended.


Patch: https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b

Show details on source website

{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.13.3"
      },
      "package": {
        "ecosystem": "PyPI",
        "name": "aiohttp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.13.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-34519"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-01T21:48:24Z",
    "nvd_published_at": "2026-04-01T21:17:00Z",
    "severity": "LOW"
  },
  "details": "### Summary\n\nAn attacker who controls the `reason` parameter when creating a `Response` may be able to inject extra headers or similar exploits.\n\n### Impact\n\nIn the unlikely situation that an application allows untrusted data to be used in the response\u0027s `reason` parameter, then an attacker could manipulate the response to send something different from what the developer intended.\n\n-----\n\nPatch: https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b",
  "id": "GHSA-mwh4-6h8g-pg8w",
  "modified": "2026-04-01T21:48:24Z",
  "published": "2026-04-01T21:48:24Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-mwh4-6h8g-pg8w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-34519"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aio-libs/aiohttp/commit/53b35a2f8869c37a133e60bf1a82a1c01642ba2b"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/aio-libs/aiohttp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U",
      "type": "CVSS_V4"
    }
  ],
  "summary": "AIOHTTP has HTTP response splitting via \\r in reason phrase"
}

GHSA-PFQJ-W6R6-G86V

Vulnerability from github – Published: 2025-03-27 18:01 – Updated: 2025-03-28 16:12
VLAI
Summary
Pitchfork HTTP Request/Response Splitting vulnerability
Details

Impact

HTTP Response Header Injection in Pitchfork Versions < 0.11.0 when used in conjunction with Rack 3

Patches

The issue was fixed in Pitchfork release 0.11.0

Workarounds

There are no known work arounds. Users must upgrade.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "RubyGems",
        "name": "pitchfork"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.11.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2025-30221"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2025-03-27T18:01:18Z",
    "nvd_published_at": "2025-03-27T15:16:02Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\nHTTP Response Header Injection in Pitchfork Versions \u003c 0.11.0 when used in conjunction with Rack 3\n\n### Patches\nThe issue was fixed in Pitchfork release 0.11.0\n\n### Workarounds\nThere are no known work arounds. Users must upgrade.",
  "id": "GHSA-pfqj-w6r6-g86v",
  "modified": "2025-03-28T16:12:43Z",
  "published": "2025-03-27T18:01:18Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Shopify/pitchfork/security/advisories/GHSA-pfqj-w6r6-g86v"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-30221"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Shopify/pitchfork/commit/17ed9b61bf9f58957065f7405b66102daf86bf55"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Shopify/pitchfork"
    },
    {
      "type": "WEB",
      "url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/pitchfork/CVE-2025-30221.yml"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Pitchfork HTTP Request/Response Splitting vulnerability"
}

GHSA-Q3G2-M552-3R9C

Vulnerability from github – Published: 2026-07-24 21:52 – Updated: 2026-07-24 21:52
VLAI
Summary
swift-nio-http2: Missing CR/LF/NUL validation in header values
Details

Summary

SwiftNIO HTTP/2 was missing validation on inbound HEADERS frames that let CR, LF, NUL, SP and other control characters reach an HTTP/1.1 backend through NIOHTTP2's HTTP/2-to-HTTP/1 codec, enabling HTTP request smuggling or response splitting.

Impact

Two related gaps in inbound header validation, against any application using HTTP2ToHTTP1Codec (or HTTP2FramePayloadToHTTP1Codec) to front an HTTP/1.1 backend:

Regular header field values were only checked against a forbidden-name list (connection, transfer-encoding, proxy-connection, keep-alive, upgrade); the value itself was never inspected. An attacker-controlled regular header field value containing CR or LF passed validation and, once serialized as name: value CRLF by the codec, terminated the field early and injected extra header lines into the outbound HTTP/1.1 message.

Pseudo-header values (:path in particular) were only checked against CR, LF and NUL. A :path value containing SP serializes into the request-target of METHOD SP request-target SP HTTP-version CRLF, so a value like /a HTTP/1.1 produces GET /a HTTP/1.1 HTTP/1.1 — a parser-differential request line depending on whether a downstream reader takes the first or last SP-delimited token as the version.

Neither of these is reachable on a stock pipeline: NIOHTTP1's outbound validator (enableOutboundHeaderValidation, on by default) already rejects these characters on write. The exposure is pipelines that skip outbound validation, or any code that reads validated-looking HTTPRequestHead.headers and forwards the values on trusting that HTTP/2 already checked them.

Fix

Fixed in 48bfd90 and 45bdf67.

Mitigation

Upgrade to 1.45.0

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "SwiftURL",
        "name": "swift-nio-http2"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.45.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-64785"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-444"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-24T21:52:10Z",
    "nvd_published_at": "2026-07-23T20:17:21Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nSwiftNIO HTTP/2 was missing validation on inbound HEADERS frames that let\nCR, LF, NUL, SP and other control characters reach an HTTP/1.1 backend\nthrough NIOHTTP2\u0027s HTTP/2-to-HTTP/1 codec, enabling HTTP request smuggling\nor response splitting.\n\n## Impact\n\nTwo related gaps in inbound header validation, against any application\nusing HTTP2ToHTTP1Codec (or HTTP2FramePayloadToHTTP1Codec) to front an\nHTTP/1.1 backend:\n\nRegular header field values were only checked against a forbidden-name\nlist (connection, transfer-encoding, proxy-connection, keep-alive,\nupgrade); the value itself was never inspected. An attacker-controlled\nregular header field value containing CR or LF passed validation and, once\nserialized as `name: value CRLF` by the codec, terminated the field early\nand injected extra header lines into the outbound HTTP/1.1 message.\n\nPseudo-header values (`:path` in particular) were only checked against\nCR, LF and NUL. A `:path` value containing SP serializes into the\nrequest-target of `METHOD SP request-target SP HTTP-version CRLF`, so a\nvalue like `/a HTTP/1.1` produces `GET /a HTTP/1.1 HTTP/1.1` \u2014 a\nparser-differential request line depending on whether a downstream reader\ntakes the first or last SP-delimited token as the version.\n\nNeither of these is reachable on a stock pipeline: NIOHTTP1\u0027s outbound\nvalidator (`enableOutboundHeaderValidation`, on by default) already rejects\nthese characters on write. The exposure is pipelines that skip outbound\nvalidation, or any code that reads validated-looking `HTTPRequestHead.headers`\nand forwards the values on trusting that HTTP/2 already checked them.\n\n## Fix\n\nFixed in 48bfd90 and 45bdf67.\n\n## Mitigation\n\nUpgrade to 1.45.0",
  "id": "GHSA-q3g2-m552-3r9c",
  "modified": "2026-07-24T21:52:10Z",
  "published": "2026-07-24T21:52:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/apple/swift-nio-http2/security/advisories/GHSA-q3g2-m552-3r9c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64785"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apple/swift-nio-http2/commit/45bdf670248be5f16ec0340e125dca285536f0fb"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apple/swift-nio-http2/commit/48bfd9067d7d1d15c4789440127a0cf36222ea43"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/apple/swift-nio-http2"
    },
    {
      "type": "WEB",
      "url": "https://github.com/apple/swift-nio-http2/releases/tag/1.45.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "swift-nio-http2: Missing CR/LF/NUL validation in header values"
}

GHSA-Q7JX-V53G-848W

Vulnerability from github – Published: 2026-07-10 00:03 – Updated: 2026-07-10 00:03
VLAI
Summary
Tesla has CRLF injection in request `Content-Type` header via `add_content_type_param`
Details

Summary

Tesla.Multipart.add_content_type_param/2 appends caller-supplied strings to the multipart Content-Type header with no validation. A param value containing \r\n splits the header line, allowing an attacker who controls any content-type parameter (charset, boundary parameter, etc.) to inject arbitrary headers into the outbound HTTP request.

Details

add_content_type_param/2 in lib/tesla/multipart.ex stores the supplied string directly in multipart.content_type_params without any CR/LF check. headers/1 then joins all params with "; " and appends the result verbatim to the Content-Type header value. Because HTTP headers are delimited by \r\n, a param containing that sequence breaks out of the header field and introduces new header lines before the adapter writes the request to the socket.

The precondition is that untrusted input reaches add_content_type_param/2, which is the normal pattern for applications that accept user-supplied charset values, file type parameters, or any other content-type extension fields.

PoC

  1. Call Tesla.Multipart.add_content_type_param/2 with a value containing \r\nX-Injected: pwned.
  2. Pass the resulting Multipart struct as the request body via any Tesla adapter.
  3. The raw request on the wire contains X-Injected: pwned as a standalone header line.

Impact

Low severity (CVSS v4.0: 2.1). Any application using tesla 0.8.0 through 1.18.2 that passes untrusted input into Tesla.Multipart.add_content_type_param/2 is affected. Consequences range from forging arbitrary outbound request headers to potential request smuggling against the upstream server. Fixed in tesla 1.18.3.

Workarounds

Validate content-type parameter strings before passing them to Tesla.Multipart.add_content_type_param/2, rejecting any value that contains \r or \n.

Reesources

  • Introduction commit: https://github.com/elixir-tesla/tesla/commit/6ebfdb9abe9c6f119408045b933d82462decd351
  • Patch commit: https://github.com/elixir-tesla/tesla/commit/23601edac5d22ba9407b427967b5bdbda201aec2
Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Hex",
        "name": "tesla"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.8.0"
            },
            {
              "fixed": "1.18.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-48596"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-93"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-10T00:03:12Z",
    "nvd_published_at": "2026-06-02T20:16:38Z",
    "severity": "LOW"
  },
  "details": "### Summary\n\n`Tesla.Multipart.add_content_type_param/2` appends caller-supplied strings to the multipart `Content-Type` header with no validation. A param value containing `\\r\\n` splits the header line, allowing an attacker who controls any content-type parameter (charset, boundary parameter, etc.) to inject arbitrary headers into the outbound HTTP request.\n\n### Details\n\n`add_content_type_param/2` in `lib/tesla/multipart.ex` stores the supplied string directly in `multipart.content_type_params` without any CR/LF check. `headers/1` then joins all params with `\"; \"` and appends the result verbatim to the `Content-Type` header value. Because HTTP headers are delimited by `\\r\\n`, a param containing that sequence breaks out of the header field and introduces new header lines before the adapter writes the request to the socket.\n\nThe precondition is that untrusted input reaches `add_content_type_param/2`, which is the normal pattern for applications that accept user-supplied charset values, file type parameters, or any other content-type extension fields.\n\n### PoC\n\n1. Call `Tesla.Multipart.add_content_type_param/2` with a value containing `\\r\\nX-Injected: pwned`.\n2. Pass the resulting `Multipart` struct as the request body via any Tesla adapter.\n3. The raw request on the wire contains `X-Injected: pwned` as a standalone header line.\n\n### Impact\n\nLow severity (CVSS v4.0: 2.1). Any application using `tesla` 0.8.0 through 1.18.2 that passes untrusted input into `Tesla.Multipart.add_content_type_param/2` is affected. Consequences range from forging arbitrary outbound request headers to potential request smuggling against the upstream server. Fixed in tesla 1.18.3.\n\n### Workarounds\n\nValidate content-type parameter strings before passing them to `Tesla.Multipart.add_content_type_param/2`, rejecting any value that contains `\\r` or `\\n`.\n\n### Reesources\n\n* Introduction commit: https://github.com/elixir-tesla/tesla/commit/6ebfdb9abe9c6f119408045b933d82462decd351\n* Patch commit: https://github.com/elixir-tesla/tesla/commit/23601edac5d22ba9407b427967b5bdbda201aec2",
  "id": "GHSA-q7jx-v53g-848w",
  "modified": "2026-07-10T00:03:12Z",
  "published": "2026-07-10T00:03:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/elixir-tesla/tesla/security/advisories/GHSA-q7jx-v53g-848w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-48596"
    },
    {
      "type": "WEB",
      "url": "https://github.com/elixir-tesla/tesla/commit/23601edac5d22ba9407b427967b5bdbda201aec2"
    },
    {
      "type": "WEB",
      "url": "https://cna.erlef.org/cves/CVE-2026-48596.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/elixir-tesla/tesla"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/EEF-CVE-2026-48596"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Tesla has CRLF injection in request `Content-Type` header via `add_content_type_param`"
}

GHSA-QCM3-7879-XCWW

Vulnerability from github – Published: 2024-08-15 21:46 – Updated: 2024-09-30 19:48
VLAI
Summary
Gateway API route matching order contradicts specification
Details

Impact

Gateway API HTTPRoutes and GRPCRoutes do not follow the match precedence specified in the Gateway API specification. In particular, request headers are matched before request methods, when the specification describes that the request methods must be respected before headers are matched (HTTPRouteRule, GRPCRouteRule).

If users create Gateway API resources that use both request headers and request methods in order to route to different destinations, then traffic may be delivered to the incorrect backend. If the backend does not have Network Policy restricting acceptable traffic to receive, then requests may access information that you did not intend for them to access.

Patches

This issue was fixed in https://github.com/cilium/cilium/pull/34109.

This issue affects: - Cilium v1.15 between v1.15.0 and v1.15.7 inclusive - Cilium v1.16.0

This issue is fixed in: - Cilium v1.15.8 - Cilium v1.16.1

Workarounds

There is no workaround for this issue.

Acknowledgements

The Cilium community has worked together with members of Cure53 and Isovalent to prepare these mitigations. Special thanks to @sayboras for remediating this issue.

Further information

If you have any questions or comments about this advisory, please reach out on Slack.

If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at security@cilium.io. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/cilium/cilium"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.16.0"
            },
            {
              "fixed": "1.16.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.16.0"
      ]
    },
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/cilium/cilium"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.15.0"
            },
            {
              "fixed": "1.15.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-42487"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113",
      "CWE-436"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-08-15T21:46:46Z",
    "nvd_published_at": "2024-08-15T21:15:16Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nGateway API HTTPRoutes and GRPCRoutes do not follow the match precedence specified in the Gateway API specification. In particular, request headers are matched before request methods, when the specification describes that the request methods must be respected before headers are matched ([HTTPRouteRule](https://gateway-api.sigs.k8s.io/reference/spec/#gateway.networking.k8s.io/v1.HTTPRouteRule), [GRPCRouteRule](https://gateway-api.sigs.k8s.io/reference/spec/#gateway.networking.k8s.io%2fv1.GRPCRouteRule)).\n\nIf users create Gateway API resources that use both request headers and request methods in order to route to different destinations, then traffic may be delivered to the incorrect backend. If the backend does not have Network Policy restricting acceptable traffic to receive, then requests may access information that you did not intend for them to access.\n\n### Patches\n\nThis issue was fixed in https://github.com/cilium/cilium/pull/34109.\n\nThis issue affects:\n- Cilium v1.15 between v1.15.0 and v1.15.7 inclusive\n- Cilium v1.16.0\n\nThis issue is fixed in:\n- Cilium v1.15.8\n- Cilium v1.16.1\n\n### Workarounds\n\nThere is no workaround for this issue.\n\n### Acknowledgements\n\nThe Cilium community has worked together with members of Cure53 and Isovalent to prepare these mitigations. Special thanks to @sayboras for remediating this issue.\n\n### Further information\n\nIf you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack).\n\nIf you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [security@cilium.io](mailto:security@cilium.io). This is a private mailing list for the Cilium security team, and your report will be treated as top priority.\n",
  "id": "GHSA-qcm3-7879-xcww",
  "modified": "2024-09-30T19:48:17Z",
  "published": "2024-08-15T21:46:46Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/cilium/cilium/security/advisories/GHSA-qcm3-7879-xcww"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-42487"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cilium/cilium/pull/34109"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cilium/cilium/commit/a3510fe4a92305822aa1a5e08cb6d6c873c8699a"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cilium/cilium/commit/d88772b9c29e370becbc4547cada6711d51edcde"
    },
    {
      "type": "WEB",
      "url": "https://github.com/cilium/cilium/commit/fe42273566a943a0f3174c87b23a195c856b51d6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/cilium/cilium"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Gateway API route matching order contradicts specification"
}

GHSA-QPF8-FQRF-8P2H

Vulnerability from github – Published: 2022-05-14 03:56 – Updated: 2025-04-12 13:05
VLAI
Details

CRLF injection vulnerability in the ServerResponse#writeHead function in Node.js 0.10.x before 0.10.47, 0.12.x before 0.12.16, 4.x before 4.6.0, and 6.x before 6.7.0 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via the reason argument.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2016-5325"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-113"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2016-10-10T16:59:00Z",
    "severity": "MODERATE"
  },
  "details": "CRLF injection vulnerability in the ServerResponse#writeHead function in Node.js 0.10.x before 0.10.47, 0.12.x before 0.12.16, 4.x before 4.6.0, and 6.x before 6.7.0 allows remote attackers to inject arbitrary HTTP headers and conduct HTTP response splitting attacks via the reason argument.",
  "id": "GHSA-qpf8-fqrf-8p2h",
  "modified": "2025-04-12T13:05:21Z",
  "published": "2022-05-14T03:56:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2016-5325"
    },
    {
      "type": "WEB",
      "url": "https://github.com/nodejs/node/commit/c0f13e56a20f9bde5a67d873a7f9564487160762"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2016:2101"
    },
    {
      "type": "WEB",
      "url": "https://nodejs.org/en/blog/vulnerability/september-2016-security-releases"
    },
    {
      "type": "WEB",
      "url": "https://security.gentoo.org/glsa/201612-43"
    },
    {
      "type": "WEB",
      "url": "http://lists.opensuse.org/opensuse-security-announce/2016-10/msg00013.html"
    },
    {
      "type": "WEB",
      "url": "http://rhn.redhat.com/errata/RHSA-2017-0002.html"
    },
    {
      "type": "WEB",
      "url": "http://www.securityfocus.com/bid/93483"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

Mitigation
Implementation

Strategy: Input Validation

Construct HTTP headers very carefully, avoiding the use of non-validated input data.

Mitigation MIT-5
Implementation

Strategy: Input Validation

  • Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. If an input does not strictly conform to specifications, reject it or transform it into something that conforms.
  • When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue."
  • Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Mitigation MIT-30
Implementation

Strategy: Output Encoding

Use and specify an output encoding that can be handled by the downstream component that is reading the output. Common encodings include ISO-8859-1, UTF-7, and UTF-8. When an encoding is not specified, a downstream component may choose a different encoding, either by assuming a default encoding or automatically inferring which encoding is being used, which can be erroneous. When the encodings are inconsistent, the downstream component might treat some character or byte sequences as special, even if they are not special in the original encoding. Attackers might then be able to exploit this discrepancy and conduct injection attacks; they even might be able to bypass protection mechanisms that assume the original encoding is also being used by the downstream component.

Mitigation MIT-20
Implementation

Strategy: Input Validation

Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

CAPEC-105: HTTP Request Splitting

An adversary abuses the flexibility and discrepancies in the parsing and interpretation of HTTP Request messages by different intermediary HTTP agents (e.g., load balancer, reverse proxy, web caching proxies, application firewalls, etc.) to split a single HTTP request into multiple unauthorized and malicious HTTP requests to a back-end HTTP agent (e.g., web server).

See CanPrecede relationships for possible consequences.

CAPEC-31: Accessing/Intercepting/Modifying HTTP Cookies

This attack relies on the use of HTTP Cookies to store credentials, state information and other critical data on client systems. There are several different forms of this attack. The first form of this attack involves accessing HTTP Cookies to mine for potentially sensitive data contained therein. The second form involves intercepting this data as it is transmitted from client to server. This intercepted information is then used by the adversary to impersonate the remote user/session. The third form is when the cookie's content is modified by the adversary before it is sent back to the server. Here the adversary seeks to convince the target server to operate on this falsified information.

CAPEC-34: HTTP Response Splitting

An adversary manipulates and injects malicious content, in the form of secret unauthorized HTTP responses, into a single HTTP response from a vulnerable or compromised back-end HTTP agent (e.g., web server) or into an already spoofed HTTP response from an adversary controlled domain/site.

See CanPrecede relationships for possible consequences.

CAPEC-85: AJAX Footprinting

This attack utilizes the frequent client-server roundtrips in Ajax conversation to scan a system. While Ajax does not open up new vulnerabilities per se, it does optimize them from an attacker point of view. A common first step for an attacker is to footprint the target environment to understand what attacks will work. Since footprinting relies on enumeration, the conversational pattern of rapid, multiple requests and responses that are typical in Ajax applications enable an attacker to look for many vulnerabilities, well-known ports, network locations and so on. The knowledge gained through Ajax fingerprinting can be used to support other attacks, such as XSS.