Vulnerability-Lookup

GHSA-333X-W4R6-6CRP

Vulnerability from github – Published: 2026-10-23 21:36 – Updated: 2026-10-23 21:36

Summary

fast-uri vulnerable to scheme injection via an unescaped first-segment colon in suffix references

Details

Impact

fast-uri's serialize(), normalize(), and resolve(), when called with the non-default option reference: 'suffix' on a reference that has no authority, emit a relative reference whose first path segment contains a bare colon without escaping it. RFC 3986 section 3.3 requires the first segment of a path-noscheme reference not to contain a colon, precisely because a bare colon makes the string reparse as an absolute URI with a scheme. fast-uri's default serialization escapes that colon, but the suffix path does not.

For example, normalize('javascript:alert(1)', { reference: 'suffix' }) returns javascript:alert(1), which reparses as a live javascript: scheme; data: and vbscript: behave the same.

Applications that serialize or normalize a relative reference with reference: 'suffix' and then treat the result as a URI can turn inert input into a live javascript:, data:, or vbscript: URL (a cross-site scripting vector), and equal() can conflate a scheme-bearing reference with a relative one. Exposure is limited to applications that use the non-default reference: 'suffix' option.

Patches

Upgrade to fast-uri 2.4.8, 3.1.9, or 4.2.3.

Workarounds

Do not use the reference: 'suffix' option on untrusted input. If suffix output is required, percent-encode a colon in the first path segment of the result before treating it as a URI.

Severity

3.7 (Low)


                  
                    CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "fast-uri"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.4.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "fast-uri"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.0.0"
            },
            {
              "fixed": "3.1.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "fast-uri"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "fixed": "4.2.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-110725"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116",
      "CWE-41"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-23T21:36:40Z",
    "nvd_published_at": "2026-10-20T07:17:08Z",
    "severity": "LOW"
  },
  "details": "### Impact\n\n`fast-uri`\u0027s `serialize()`, `normalize()`, and `resolve()`, when called with the non-default option `reference: \u0027suffix\u0027` on a reference that has no authority, emit a relative reference whose first path segment contains a bare colon without escaping it. RFC 3986 section 3.3 requires the first segment of a `path-noscheme` reference not to contain a colon, precisely because a bare colon makes the string reparse as an absolute URI with a scheme. `fast-uri`\u0027s default serialization escapes that colon, but the suffix path does not.\n\nFor example, `normalize(\u0027javascript:alert(1)\u0027, { reference: \u0027suffix\u0027 })` returns `javascript:alert(1)`, which reparses as a live `javascript:` scheme; `data:` and `vbscript:` behave the same.\n\nApplications that serialize or normalize a relative reference with `reference: \u0027suffix\u0027` and then treat the result as a URI can turn inert input into a live `javascript:`, `data:`, or `vbscript:` URL (a cross-site scripting vector), and `equal()` can conflate a scheme-bearing reference with a relative one. Exposure is limited to applications that use the non-default `reference: \u0027suffix\u0027` option.\n\n### Patches\n\nUpgrade to `fast-uri` `2.4.8`, `3.1.9`, or `4.2.3`.\n\n### Workarounds\n\nDo not use the `reference: \u0027suffix\u0027` option on untrusted input. If suffix output is required, percent-encode a colon in the first path segment of the result before treating it as a URI.",
  "id": "GHSA-333x-w4r6-6crp",
  "modified": "2026-10-23T21:36:40Z",
  "published": "2026-10-23T21:36:40Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/security/advisories/GHSA-333x-w4r6-6crp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-110725"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/commit/39e6493c1356f30a0084171627eb266786e1620e"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/commit/a9b8d67353630aab053cd727cf629023dd018d2b"
    },
    {
      "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/v2.4.8"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/releases/tag/v3.1.9"
    },
    {
      "type": "WEB",
      "url": "https://github.com/fastify/fast-uri/releases/tag/v4.2.3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "fast-uri vulnerable to scheme injection via an unescaped first-segment colon in suffix references"
}

CVE-2026-110725 (GCVE-0-2026-110725)

Vulnerability from cvelistv5 – Published: 2026-10-20 07:06 – Updated: 2026-10-20 19:14

Title

fast-uri vulnerable to scheme injection via an unescaped first-segment colon in suffix references

Summary

fast-uri is a dependency-free RFC 3986 URI parser and serializer for Node.js. In versions before 2.4.8, from 3.0.0 through 3.1.8, and from 4.0.0 through 4.2.2, when serialize(), normalize(), or resolve() are called with the non-default option reference set to suffix on a reference that has no authority, the emitted relative reference can contain a bare colon in its first path segment without escaping it, even though RFC 3986 forbids that because it makes the string reparse as an absolute URI with a scheme. An application that serializes or normalizes a relative reference with the suffix option and then treats the result as a URI can turn inert input into a live javascript, data, or vbscript URL, a cross-site scripting vector, and the equal() comparison can conflate a scheme-bearing reference with a relative one. Exposure is limited to applications using the non-default suffix reference option. The issue is fixed in fast-uri 2.4.8, 3.1.9, and 4.2.3, and users should upgrade to one of these versions or later. As a workaround, avoid the suffix reference option on untrusted input, or percent-encode a colon in the first path segment of the result before treating it as a URI.

Severity

3.7 (Low)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-10-20 19:14 UTC

CWE

CWE-41 - Improper Resolution of Path Equivalence
CWE-116 - Improper Encoding or Escaping of Output

Assigner

openjs CNA under the redhat root

CNA scorecard C 65/100 over 121 records in the last 180 days details

References

2 references

URL	Tags
https://github.com/fastify/fast-uri/security/advi…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version
fast-uri	fast-uri	Affected: 0 , < 2.4.8 (semver) Unaffected: 2.4.8 (semver) Affected: 3.0.0 , < 3.1.9 (semver) Unaffected: 3.1.9 (semver) Affected: 4.0.0 , < 4.2.3 (semver) Unaffected: 4.2.3 (semver)

Credits

UlisesGascon mcollina

Show details on NVD website

JSON

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Sightings

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Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

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