{
  "containers": {
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      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-112880",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-26T15:00:47.038622Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-26T15:35:50.632Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://repo.hex.pm",
          "cpes": [
            "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "hackney_http_connect"
          ],
          "packageName": "hackney",
          "packageURL": "pkg:hex/hackney",
          "product": "hackney",
          "programFiles": [
            "src/hackney_http_connect.erl"
          ],
          "programRoutines": [
            {
              "name": "hackney_http_connect:connect/4"
            },
            {
              "name": "hackney_http_connect:do_handshake_with_auth/9"
            },
            {
              "name": "hackney_http_connect:handle_proxy_auth/11"
            }
          ],
          "repo": "https://github.com/benoitc/hackney",
          "vendor": "benoitc",
          "versions": [
            {
              "lessThan": "4.9.0",
              "status": "affected",
              "version": "2.0.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://github.com",
          "cpes": [
            "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*"
          ],
          "defaultStatus": "unaffected",
          "modules": [
            "hackney_http_connect"
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          "packageName": "benoitc/hackney",
          "packageURL": "pkg:github/benoitc/hackney",
          "product": "hackney",
          "programFiles": [
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          "programRoutines": [
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              "name": "hackney_http_connect:connect/4"
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            {
              "name": "hackney_http_connect:do_handshake_with_auth/9"
            },
            {
              "name": "hackney_http_connect:handle_proxy_auth/11"
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          ],
          "repo": "https://github.com/benoitc/hackney",
          "vendor": "benoitc",
          "versions": [
            {
              "lessThan": "5ee7d7d19eba27e774667d472feb1e93a08af7f9",
              "status": "affected",
              "version": "5df5a74a2817d5b12880d217db33253ff1fae1b5",
              "versionType": "git"
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      "configurations": [
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          "lang": "en",
          "supportingMedia": [
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              "value": "\u003cp\u003eThe client connects through an HTTP CONNECT proxy with the \u003ccode\u003eproxy_auth_fun\u003c/code\u003e option set, and the callback builds its result from data an untrusted party can influence, such as the proxy\u0027s 407 challenge headers. Deployments without \u003ccode\u003eproxy_auth_fun\u003c/code\u003e, or whose callback returns a fixed credential, are not affected.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "The client connects through an HTTP CONNECT proxy with the `proxy_auth_fun` option set, and the callback builds its result from data an untrusted party can influence, such as the proxy\u0027s 407 challenge headers. Deployments without `proxy_auth_fun`, or whose callback returns a fixed credential, are not affected."
            }
          ],
          "value": "The client connects through an HTTP CONNECT proxy with the proxy_auth_fun option set, and the callback builds its result from data an untrusted party can influence, such as the proxy\u0027s 407 challenge headers. Deployments without proxy_auth_fun, or whose callback returns a fixed credential, are not affected."
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:benoitc:hackney:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.9.0",
                  "versionStartIncluding": "2.0.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ],
          "operator": "AND"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Daniel Coles"
        },
        {
          "lang": "en",
          "type": "reporter",
          "value": "Daniel Coles"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Benoit Chesneau"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Jonatan M\u00e4nnchen / EEF"
        }
      ],
      "dateAssigned": "2026-10-26T10:18:44.000Z",
      "datePublic": "2026-10-25T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
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              "value": "\u003cp\u003eImproper Neutralization of CRLF Sequences in HTTP Headers (\u0027HTTP Request/Response Splitting\u0027) vulnerability in \u003ccode\u003ehackney_http_connect\u003c/code\u003e in benoitc hackney allows HTTP Request Splitting via the value a \u003ccode\u003eproxy_auth_fun\u003c/code\u003e callback returns. After a 407 response from an HTTP CONNECT proxy, \u003ccode\u003ehackney_http_connect:handle_proxy_auth/11\u003c/code\u003e calls the caller\u0027s \u003ccode\u003eproxy_auth_fun\u003c/code\u003e with the status code and the response headers and writes the returned binary into the \u003ccode\u003eProxy-Authorization\u003c/code\u003e line of the CONNECT retry without checking it. A CR, LF or NUL byte in that value adds header lines to the request sent to the proxy.\u003c/p\u003e\n\u003cp\u003eThe value is attacker-influenced when the callback derives it from untrusted data, for example from the proxy\u0027s challenge headers. Other caller-supplied values on the CONNECT path, such as the target host and the request headers, were already checked for control bytes.\u003c/p\u003e\n\u003cp\u003eThis issue affects hackney: from 2.0.0 before 4.9.0.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Improper Neutralization of CRLF Sequences in HTTP Headers (\u0027HTTP Request/Response Splitting\u0027) vulnerability in `hackney_http_connect` in benoitc hackney allows HTTP Request Splitting via the value a `proxy_auth_fun` callback returns. After a 407 response from an HTTP CONNECT proxy, `hackney_http_connect:handle_proxy_auth/11` calls the caller\u0027s `proxy_auth_fun` with the status code and the response headers and writes the returned binary into the `Proxy-Authorization` line of the CONNECT retry without checking it. A CR, LF or NUL byte in that value adds header lines to the request sent to the proxy.\n\nThe value is attacker-influenced when the callback derives it from untrusted data, for example from the proxy\u0027s challenge headers. Other caller-supplied values on the CONNECT path, such as the target host and the request headers, were already checked for control bytes.\n\nThis issue affects hackney: from 2.0.0 before 4.9.0."
            }
          ],
          "value": "Improper Neutralization of CRLF Sequences in HTTP Headers (\u0027HTTP Request/Response Splitting\u0027) vulnerability in hackney_http_connect in benoitc hackney allows HTTP Request Splitting via the value a proxy_auth_fun callback returns. After a 407 response from an HTTP CONNECT proxy, hackney_http_connect:handle_proxy_auth/11 calls the caller\u0027s proxy_auth_fun with the status code and the response headers and writes the returned binary into the Proxy-Authorization line of the CONNECT retry without checking it. A CR, LF or NUL byte in that value adds header lines to the request sent to the proxy.\n\nThe value is attacker-influenced when the callback derives it from untrusted data, for example from the proxy\u0027s challenge headers. Other caller-supplied values on the CONNECT path, such as the target host and the request headers, were already checked for control bytes.\n\nThis issue affects hackney: from 2.0.0 before 4.9.0."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-105",
          "descriptions": [
            {
              "lang": "en",
              "supportingMedia": [
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                  "value": "\u003cp\u003eA party who controls what the application\u0027s \u003ccode\u003eproxy_auth_fun\u003c/code\u003e returns, for instance through the challenge headers of a proxy it can influence, can add header lines to the CONNECT request the client sends to its proxy.\u003c/p\u003e"
                },
                {
                  "base64": false,
                  "type": "text/markdown",
                  "value": "A party who controls what the application\u0027s `proxy_auth_fun` returns, for instance through the challenge headers of a proxy it can influence, can add header lines to the CONNECT request the client sends to its proxy."
                }
              ],
              "value": "A party who controls what the application\u0027s proxy_auth_fun returns, for instance through the challenge headers of a proxy it can influence, can add header lines to the CONNECT request the client sends to its proxy."
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "LOCAL",
            "baseScore": 2.1,
            "baseSeverity": "LOW",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "LOW",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "LOW",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-113",
              "description": "CWE-113 Improper Neutralization of CRLF Sequences in HTTP Headers (\u0027HTTP Request/Response Splitting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-26T13:48:46.589Z",
        "orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
        "shortName": "EEF"
      },
      "references": [
        {
          "name": "hackney 4.9.0 release notes",
          "tags": [
            "vendor-advisory",
            "related"
          ],
          "url": "https://github.com/benoitc/hackney/releases/tag/4.9.0"
        },
        {
          "name": "EEF CNA record for CVE-2026-112880",
          "tags": [
            "related"
          ],
          "url": "https://cna.erlef.org/cves/CVE-2026-112880.html"
        },
        {
          "name": "OSV record EEF-CVE-2026-112880",
          "tags": [
            "related"
          ],
          "url": "https://osv.dev/vulnerability/EEF-CVE-2026-112880"
        },
        {
          "name": "Refuse CR/LF/NUL in the proxy_auth_fun result (benoitc/hackney#989)",
          "tags": [
            "related"
          ],
          "url": "https://github.com/benoitc/hackney/pull/989"
        },
        {
          "name": "Introducing commit 5df5a74 in benoitc/hackney",
          "tags": [
            "related"
          ],
          "url": "https://github.com/benoitc/hackney/commit/5df5a74a2817d5b12880d217db33253ff1fae1b5"
        },
        {
          "name": "Fix commit 5ee7d7d in benoitc/hackney",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/benoitc/hackney/commit/5ee7d7d19eba27e774667d472feb1e93a08af7f9"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "CRLF injection in Proxy-Authorization header built from proxy_auth_fun in hackney",
      "workarounds": [
        {
          "lang": "en",
          "supportingMedia": [
            {
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              "value": "\u003cp\u003eCheck the value your \u003ccode\u003eproxy_auth_fun\u003c/code\u003e is about to return for CR, LF and NUL bytes and return \u003ccode\u003e{error, Reason}\u003c/code\u003e instead when one is present. The callback runs in the application, so the check can be made there.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "Check the value your `proxy_auth_fun` is about to return for CR, LF and NUL bytes and return `{error, Reason}` instead when one is present. The callback runs in the application, so the check can be made there."
            }
          ],
          "value": "Check the value your proxy_auth_fun is about to return for CR, LF and NUL bytes and return {error, Reason} instead when one is present. The callback runs in the application, so the check can be made there."
        }
      ],
      "x_technicalAnalysis": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003e\u003cstrong\u003e1. Challenge.\u003c/strong\u003e \u003ccode\u003ehackney_http_connect:do_handshake_with_auth/9\u003c/code\u003e in \u003ccode\u003esrc/hackney_http_connect.erl\u003c/code\u003e sends the CONNECT request to the proxy. When the proxy answers 407 and the \u003ccode\u003eproxy_auth_fun\u003c/code\u003e option is set, it hands the status code and the parsed response headers to \u003ccode\u003ehackney_http_connect:handle_proxy_auth/11\u003c/code\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. Callback result.\u003c/strong\u003e \u003ccode\u003ehandle_proxy_auth/11\u003c/code\u003e calls the caller\u0027s \u003ccode\u003eproxy_auth_fun\u003c/code\u003e with those two values. On \u003ccode\u003e{ok, AuthHeader}\u003c/code\u003e it removes any existing \u003ccode\u003eProxy-Authorization\u003c/code\u003e header and appends the binary \u003ccode\u003e\u0026lt;\u0026lt;\"Proxy-Authorization: \", AuthHeader/binary\u0026gt;\u0026gt;\u003c/code\u003e to the header list, then retries the handshake with it.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3. Splitting.\u003c/strong\u003e The header list is joined with CRLF into the CONNECT request. A CR, LF or NUL byte inside \u003ccode\u003eAuthHeader\u003c/code\u003e therefore ends the \u003ccode\u003eProxy-Authorization\u003c/code\u003e line early and the rest is sent as further header lines. The target host and the request headers go through control-byte checks on this path; the callback result did not. The fix applies the same \u003ccode\u003ehas_ctl_bytes/1\u003c/code\u003e check to it and returns \u003ccode\u003e{error, {proxy_auth_error, invalid_header}}\u003c/code\u003e.\u003c/p\u003e"
            },
            {
              "base64": false,
              "type": "text/markdown",
              "value": "**1. Challenge.** `hackney_http_connect:do_handshake_with_auth/9` in `src/hackney_http_connect.erl` sends the CONNECT request to the proxy. When the proxy answers 407 and the `proxy_auth_fun` option is set, it hands the status code and the parsed response headers to `hackney_http_connect:handle_proxy_auth/11`.\n\n**2. Callback result.** `handle_proxy_auth/11` calls the caller\u0027s `proxy_auth_fun` with those two values. On `{ok, AuthHeader}` it removes any existing `Proxy-Authorization` header and appends the binary `\u003c\u003c\"Proxy-Authorization: \", AuthHeader/binary\u003e\u003e` to the header list, then retries the handshake with it.\n\n**3. Splitting.** The header list is joined with CRLF into the CONNECT request. A CR, LF or NUL byte inside `AuthHeader` therefore ends the `Proxy-Authorization` line early and the rest is sent as further header lines. The target host and the request headers go through control-byte checks on this path; the callback result did not. The fix applies the same `has_ctl_bytes/1` check to it and returns `{error, {proxy_auth_error, invalid_header}}`."
            }
          ],
          "value": "1. Challenge. hackney_http_connect:do_handshake_with_auth/9 in src/hackney_http_connect.erl sends the CONNECT request to the proxy. When the proxy answers 407 and the proxy_auth_fun option is set, it hands the status code and the parsed response headers to hackney_http_connect:handle_proxy_auth/11.\n\n2. Callback result. handle_proxy_auth/11 calls the caller\u0027s proxy_auth_fun with those two values. On {ok, AuthHeader} it removes any existing Proxy-Authorization header and appends the binary \u003c\u003c\"Proxy-Authorization: \", AuthHeader/binary\u003e\u003e to the header list, then retries the handshake with it.\n\n3. Splitting. The header list is joined with CRLF into the CONNECT request. A CR, LF or NUL byte inside AuthHeader therefore ends the Proxy-Authorization line early and the rest is sent as further header lines. The target host and the request headers go through control-byte checks on this path; the callback result did not. The fix applies the same has_ctl_bytes/1 check to it and returns {error, {proxy_auth_error, invalid_header}}."
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db",
    "assignerShortName": "EEF",
    "cveId": "CVE-2026-112880",
    "datePublished": "2026-10-26T13:48:46.589Z",
    "dateReserved": "2026-10-26T10:15:01.166Z",
    "dateUpdated": "2026-10-26T15:35:50.632Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}