GHSA-V39H-62P7-JPJC

Vulnerability from github – Published: 2026-05-08 19:13 – Updated: 2026-09-01 15:30
VLAI
Summary
fast-uri vulnerable to host confusion via percent-encoded authority delimiters
Details

Impact

fast-uri v3.1.1 and earlier decodes percent-encoded authority delimiters (%40 as @, %3A as :) inside the host component and serializes them back as raw characters. This changes the URI structure, turning a hostname into userinfo plus a different host.

For example, http://trusted.com%40evil.com/ normalizes to http://trusted.com@evil.com/, which reparses as host evil.com with userinfo trusted.com.

Applications that normalize untrusted URLs before host allowlist checks, redirect validation, or outbound request routing can be steered to a different authority than the original URL appeared to contain.

Patches

Upgrade to fast-uri >= 3.1.2, or if you are in the v2.x release line, v2.4.1

Workarounds

None. Upgrade to the patched version.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.1.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "fast-uri"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 2.4.0"
      },
      "package": {
        "ecosystem": "npm",
        "name": "fast-uri"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-6322"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-140",
      "CWE-436"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T19:13:01Z",
    "nvd_published_at": "2026-05-05T11:16:33Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\n`fast-uri` v3.1.1 and earlier decodes percent-encoded authority delimiters (`%40` as `@`, `%3A` as `:`) inside the host component and serializes them back as raw characters. This changes the URI structure, turning a hostname into userinfo plus a different host.\n\nFor example, `http://trusted.com%40evil.com/` normalizes to `http://trusted.com@evil.com/`, which reparses as host `evil.com` with userinfo `trusted.com`.\n\nApplications that normalize untrusted URLs before host allowlist checks, redirect validation, or outbound request routing can be steered to a different authority than the original URL appeared to contain.\n\n### Patches\n\nUpgrade to `fast-uri` \u003e= 3.1.2, or if you are in the v2.x release line, v2.4.1\n\n### Workarounds\n\nNone. Upgrade to the patched version.",
  "id": "GHSA-v39h-62p7-jpjc",
  "modified": "2026-09-01T15:30:39Z",
  "published": "2026-05-08T19:13:01Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/security/advisories/GHSA-v39h-62p7-jpjc"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6322"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:41928"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:41951"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:42078"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:42142"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:43038"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:54395"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:54555"
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      "url": "https://access.redhat.com/errata/RHSA-2026:56366"
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      "url": "https://access.redhat.com/errata/RHSA-2026:56968"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:57013"
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      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:57487"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:60520"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:60855"
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      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:61783"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-6322"
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    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2466684"
    },
    {
      "type": "WEB",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/fastify/fast-uri"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/releases/tag/v2.4.1"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/releases/tag/v3.1.2"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6322.json"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:25271"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:25273"
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      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:26225"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:26234"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:28571"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:29197"
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      "url": "https://access.redhat.com/errata/RHSA-2026:34160"
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    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:34374"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:34766"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:34770"
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      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:36651"
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    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:36754"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:37186"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:37385"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:37628"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:40118"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:40945"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:41066"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "fast-uri vulnerable to host confusion via percent-encoded authority delimiters"
}



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