GitHub Advisoryadvisory · npm
GHSA-83w8-p2f5-377r @fastify/static vulnerable to route guard bypass via path traversal
HIGH
Official page ↗
- Aliases
- CVE-2026-15074
- Ecosystem
- npm
- Packages
- @fastify/static
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Weaknesses
- CWE-22
- Reviewed
- 2026-07-24
Affected packages
• npm @fastify/static: < 10.1.1 → fixed in 10.1.1
Description
Impact
`@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 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.
Applications 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.
Patches
Upgrade to `@fastify/static` 10.1.1.
Workarounds
Do not use route-based middlewares or guards to protect files served by `@fastify/static`.
Related
Alias · CVE (1)
- CVE-2026-15074 @fastify/static up to and including version 10.1.0 fails to reject dot-dot path segments in request pathnames before the file-resolution… vulnerability
Weakness · CWE (1)
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory weakness
References
- https://github.com/fastify/fastify-static/security/advisories/GHSA-83w8-p2f5-377r web
- https://nvd.nist.gov/vuln/detail/CVE-2026-15074 advisory
- https://github.com/fastify/fastify-static/commit/db4276f846ba56b21f93768cd6636ee5e2fc58b1 web
- https://cna.openjsf.org/security-advisories.html web
- https://github.com/fastify/fastify-static package
- https://github.com/fastify/fastify-static/releases/tag/v10.1.1 web