{"id":"CVE-2026-15074","aliases":["GHSA-83w8-p2f5-377r"],"title":"@fastify/static vulnerable to route guard bypass via path traversal","summary":"@fastify/static vulnerable to route guard bypass via path traversal","severity":"high","cvss":7.5,"cwe":["CWE-22"],"vendor":"fastify","product":"@fastify/static","ecosystem":"npm","affected":["@fastify/static <= 10.1.0"],"patched":["@fastify/static 10.1.1"],"published":"2026-07-24","updated":"2026-07-24","source":"GHSA","sourceUrl":"https://github.com/advisories/GHSA-83w8-p2f5-377r","references":[{"url":"https://github.com/fastify/fastify-static/security/advisories/GHSA-83w8-p2f5-377r"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-15074"},{"url":"https://github.com/fastify/fastify-static/commit/db4276f846ba56b21f93768cd6636ee5e2fc58b1"},{"url":"https://cna.openjsf.org/security-advisories.html"},{"url":"https://github.com/fastify/fastify-static/releases/tag/v10.1.1"},{"url":"https://github.com/advisories/GHSA-83w8-p2f5-377r"}],"tags":["ghsa","npm"],"epss":0.00672,"epssPercentile":0.50224,"ingestedAt":"2026-07-24T17:34:27.748Z","slug":"CVE-2026-15074","body":"## Overview\n\n### Impact\n\n`@fastify/static` is vulnerable to a bypass of route-based middleware and guards via non-leading `..` and `%2E%2E` path segments. `find-my-way` does not normalize `..` when matching routes, so a request such as `/foo/../deep/secret.txt` matches the static plugin's catch-all instead of the guarded `/deep/*`. The `getPathnameForSend` helper introduced by the fix for [GHSA-x428-ghpx-8j92](https://github.com/fastify/fastify-static/security/advisories/GHSA-x428-ghpx-8j92) only guards against the `%2F` variant; `..` and `%2E%2E` survive the `decodeURI` + `encodeURI` round-trip and are then collapsed away by `@fastify/send`'s `path.normalize` before its own traversal guard runs.\n\nApplications that rely on route-based middleware or guards to protect files served by `@fastify/static` can be bypassed with non-leading dot-dot path segments.\n\n### Patches\n\nUpgrade to `@fastify/static` 10.1.1.\n\n### Workarounds\n\nDo not use route-based middlewares or guards to protect files served by `@fastify/static`.\n\n## Affected packages\n\n- `@fastify/static <= 10.1.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `@fastify/static 10.1.1`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}