{"id":"CVE-2026-6414","aliases":["GHSA-x428-ghpx-8j92"],"url":"https://o3.security/vulnerability/CVE-2026-6414","summary":"@fastify/static vulnerable to route guard bypass via encoded path separators","details":"### Impact\n\n`@fastify/static` v9.1.0 and earlier decodes percent-encoded path separators (`%2F`) before filesystem resolution, but Fastify's router treats them as literal characters. This creates a routing mismatch: route guards on `/admin/*` do not match `/admin%2Fsecret.html`, but @fastify/static decodes it to `/admin/secret.html` and serves the file.\n\nApplications that rely on route-based middleware or guards to protect files served by @fastify/static can be bypassed with encoded path separators.\n\n### Patches\n\nUpgrade to `@fastify/static` >= 9.1.1.\n\n### Workarounds\n\nNone. Upgrade to the patched version.","published":"2026-04-16T13:09:03.526Z","modified":"2026-10-28T02:31:06.858952126Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":{"score":0.00413,"percentile":0.3512,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@fastify/static","fixedVersion":"9.1.1"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://cna.openjsf.org/security-advisories.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6414.json"},{"type":"ADVISORY","url":"https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92"},{"type":"ADVISORY","url":"https://github.com/fastify/middie/security/advisories/GHSA-cxrg-g7r8-w69p"},{"type":"ADVISORY","url":"https://github.com/honojs/hono/security/advisories/GHSA-q5qw-h33p-qvwr"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6414"},{"type":"PACKAGE","url":"https://github.com/fastify/fastify-static"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T02:31:06.858952126Z"}}