fast-uri vulnerable to host confusion via skipped IDN canonicalization on scheme-relative references
漏洞描述
### Impact `fast-uri` canonicalizes a host to its ASCII form only when the input carries an explicit scheme. When `resolve()` 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 one `resolve()` returned. An application that resolves an untrusted reference with `fast-uri` and 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-uri` 2.4.5, 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. Source Code Location: https://github.com/fastify/fast-uri Affected Packages: - npm:fast-uri, affected >= 2.4.2, < 2.4.5, patched in 2.4.5 - npm:fast-uri, affected >= 3.1.3, < 3.1.6, patched in 3.1.6 - npm:fast-uri, affected >= 4.0.1, < 4.1.3, patched in 4.1.3 CWEs: - CWE-436: Interpretation Conflict CVSS: - Primary: score 7.5, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N - CVSS_V3: score 7.5, CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N 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/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 - https://github.com/advisories/GHSA-5jgf-p345-68v8