{"id":"GHSA-wjr9-j795-jxcr","revision":"11f81a8267b740beb7fe02dcec40670d","records":[{"revision":"11f81a8267b740beb7fe02dcec40670d","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-wjr9-j795-jxcr","aliases":["CVE-2026-110180"],"title":"fast-uri vulnerable to host confusion via unchecked WHATWG host canonicalization","description":"### Impact\n\n`fast-uri` versions `>= 2.4.2, <= 2.4.7`, `>= 3.1.3, <= 3.1.8`, and `>= 4.0.1, <= 4.2.2` can silently rewrite the host of an HTTP-family URL (`http`, `https`, `ws`, `wss`, or any scheme with `domainHost: true`). For those schemes `canonicalizeHost()` passes the parsed host to the WHATWG `URL` parser and adopts its `.hostname` without checking that the parser read the whole input as a host. RFC 3986 permits `@` inside the host group and the WHATWG parser strips TAB, LF, and CR, so the authority `fast-uri` reports is rewritten by that second parser with no `error` set: data before an `@` is dropped and whitespace is removed.\n\nFor example, `fast-uri` parses `http://a@b@evil.example/` to host `evil.example` (dropping the `b` segment), and a host containing a raw TAB, CR, or LF has those characters stripped. `equal()` then treats a whitespace-smuggled host as the same as the clean one, and `resolve()` rewrites the authority the same way.\n\nApplications that use `fast-uri` to enforce host-based policy (denylists, loopback filtering, redirect validation, outbound proxy routing) on one representation, such as the raw input, see a policy/use desync: the canonical host `fast-uri` returns differs from what was checked, and traffic can be steered to an unintended destination.\n\n### Patches\n\nUpgrade to `fast-uri` `2.4.8`, `3.1.9`, or `4.2.3`.\n\n### Workarounds\n\nReject URIs whose authority contains more than one `@`, or contains TAB, CR, or LF, before calling `fast-uri`. Alternatively, treat any non-empty `parse(x).error` as fatal, and compare hosts only from the same `parse()` result.","state":0,"publishedAt":"2026-10-23T21:37:59+00:00","modifiedAt":"2026-10-23T21:45:04.8920547+00:00","affected":[{"ecosystem":"npm","name":"fast-uri","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"2.4.2"},{"kind":"fixed","version":"2.4.8"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"fast-uri","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"3.1.3"},{"kind":"fixed","version":"3.1.9"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"fast-uri","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"4.0.1"},{"kind":"fixed","version":"4.2.3"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"MODERATE"}],"references":["https://github.com/fastify/fast-uri/security/advisories/GHSA-wjr9-j795-jxcr","https://nvd.nist.gov/vuln/detail/CVE-2026-110180","https://github.com/fastify/fast-uri/commit/58c183d0b168ad87f98773266444ce1f6375803a","https://github.com/fastify/fast-uri/commit/ddfc6a51122dfce0365655f04479fc3adb7f6b3c","https://github.com/fastify/fast-uri/commit/f6d46dfeab025d0c440485f4ae29fa4f14707646","https://cna.openjsf.org/security-advisories.html","https://github.com/fastify/fast-uri","https://github.com/fastify/fast-uri/releases/tag/v2.4.8","https://github.com/fastify/fast-uri/releases/tag/v3.1.9","https://github.com/fastify/fast-uri/releases/tag/v4.2.3"],"sourceUrl":"https://github.com/advisories/GHSA-wjr9-j795-jxcr","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-wjr9-j795-jxcr","identifiers":["GHSA-wjr9-j795-jxcr","CVE-2026-110180"]},"retained":false,"historicalAffected":[]}],"coverage":[]}