GHSA-5jgf-p345-68v8
Suggest an improvement- Source
- https://github.com/advisories/GHSA-5jgf-p345-68v8
- Import Source
- https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-5jgf-p345-68v8/GHSA-5jgf-p345-68v8.json
- JSON Data
- https://api.osv.dev/v1/vulns/GHSA-5jgf-p345-68v8
- Aliases
- Related
- Published
- 2026-09-02T15:44:30Z
- Modified
- 2026-09-03T16:25:59.089522632Z
- Severity
-
- 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
- Summary
- fast-uri vulnerable to host confusion via skipped IDN canonicalization on scheme-relative references
- Details
-
Impact
fast-uricanonicalizes a host to its ASCII form only when the input carries an explicit scheme. Whenresolve()resolves a scheme-relative reference (//host/) against a scheme-bearing base, it still emits the host verbatim even though the effective scheme is known, so re-parsing the resolved URI yields a different host than the oneresolve()returned. An application that resolves an untrusted reference withfast-uriand then checks or routes on the resulting host can make a policy decision on one host and reach another. This is an incomplete-fix variant of CVE-2026-13676, whose IDN canonicalization was applied only to the scheme-bearing form.Patches
Upgrade to
fast-uri2.4.5, 3.1.6, or 4.1.3.resolve()now canonicalizes the host once the effective scheme is known, and fails closed if a raw non-ASCII host cannot be converted.Workarounds
Resolve scheme-relative references against a base that carries a scheme before performing any host-policy or origin check.
- Database specific
{ "nvd_published_at": "2026-08-24T10:16:40Z", "github_reviewed_at": "2026-09-02T15:44:30Z", "severity": "HIGH", "github_reviewed": true, "cwe_ids": [ "CWE-436" ] }- References
-
- https://github.com/fastify/fast-uri/security/advisories/GHSA-5jgf-p345-68v8
- https://nvd.nist.gov/vuln/detail/CVE-2026-75931
- https://github.com/fastify/fast-uri/commit/0256bc8d1f28b5d0ac657faf67e2411a189dfcb5
- https://github.com/fastify/fast-uri/commit/444ecdad447db2cc23c4d422acc6f0daa6fa8eef
- https://github.com/fastify/fast-uri/commit/4e4ebd8b245f6ca16e448203559eea3e545453a3
- https://cna.openjsf.org/security-advisories.html
- https://github.com/fastify/fast-uri
- https://github.com/fastify/fast-uri/releases/tag/v2.4.5
- https://github.com/fastify/fast-uri/releases/tag/v3.1.6
- https://github.com/fastify/fast-uri/releases/tag/v4.1.3
Affected packages
npm / fast-uri
Package
- Name
- fast-uri
- View open source insights on deps.dev
- Purl
- pkg:npm/fast-uri
npm / fast-uri
Package
- Name
- fast-uri
- View open source insights on deps.dev
- Purl
- pkg:npm/fast-uri
npm / fast-uri
Package
- Name
- fast-uri
- View open source insights on deps.dev
- Purl
- pkg:npm/fast-uri