{"id":"CVE-2026-76169","revision":"73037286586a491d82f5b62e2dd5b3ed","records":[{"revision":"73037286586a491d82f5b62e2dd5b3ed","observedAt":"2026-10-25T16:19:04.694+00:00","statement":{"source":"nvd","id":"CVE-2026-76169","aliases":[],"title":"fastify versions >= 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler. The inter…","description":"fastify versions >= 4.0.0 and before 5.12.2 can route a malformed URL sent under one plugin prefix to the custom not-found handler of a different sibling plugin, and invoke it without the preHandler hook declared for that handler. The internal not-found router for encapsulated handlers dispatches malformed paths through a single shared handler pointer before URL decoding, ignoring the prefix and skipping the selected handler's normal lifecycle. An unauthenticated attacker can therefore reach an authentication-protected private fallback through an unrelated public prefix and read its full response, bypassing the authentication hook and breaking prefix encapsulation. Users should upgrade to fastify 5.12.2 or later.","state":0,"publishedAt":"2026-09-04T10:17:12.02+00:00","modifiedAt":"2026-09-15T20:07:46.7+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":7.5,"severity":"HIGH"}],"references":["https://cna.openjsf.org/security-advisories.html","https://github.com/fastify/fastify/security/advisories/GHSA-p68q-wchp-6fh7"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-76169","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-288"],"productCriteria":["cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-09-04T10:17:12.020","lastModified":"2026-09-15T20:07:46.700"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-76169","identifiers":["CVE-2026-76169"]},"retained":false,"historicalAffected":[]}],"coverage":[]}