{"id":"CVE-2026-33808","revision":"87e54a0d1a544e078fa24779bbc33a9a","records":[{"revision":"87e54a0d1a544e078fa24779bbc33a9a","observedAt":"2026-10-27T09:02:55.767+00:00","statement":{"source":"nvd","id":"CVE-2026-33808","aliases":[],"title":"Impact@fastify/express v4.0.4 and earlier fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via dupl…","description":"Impact@fastify/express v4.0.4 and earlier fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via duplicate slashes when ignoreDuplicateSlashes is enabled, or via semicolon delimiters when useSemicolonDelimiter is enabled. In both cases, Fastify router normalizes the URL and matches the route, but @fastify/express passes the original un-normalized URL to Express middleware, which fails to match and is skipped. An unauthenticated attacker can access protected routes by manipulating the URL path.\n\nPatchesUpgrade to @fastify/express v4.0.5 or later.","state":0,"publishedAt":"2026-04-15T10:16:48.453+00:00","modifiedAt":"2026-10-26T22:10:00.163+00:00","affected":[],"metrics":[{"system":"CVSS 4.0 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","score":9.1,"severity":"CRITICAL"},{"system":"CVSS 3.1 · nvd@nist.gov · Primary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","score":9.1,"severity":"CRITICAL"}],"references":["https://cna.openjsf.org/security-advisories.html","https://github.com/fastify/fastify-express/security/advisories/GHSA-6hw5-45gm-fj88"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-33808","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Analyzed","weaknesses":["CWE-436"],"productCriteria":["cpe:2.3:a:fastify:fastify\\/express:*:*:*:*:*:node.js:*:*"],"sourceDates":{"published":"2026-04-15T10:16:48.453","lastModified":"2026-10-26T22:10:00.163"},"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-2026-33808","identifiers":["CVE-2026-33808"]},"retained":false,"historicalAffected":[]}],"coverage":[]}