GHSA-83w8-p2f5-377r
@fastify/static vulnerable to route guard bypass via path traversal
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @fastify/static | < 10.1.1 | 10.1.1 |
Details
As written in the advisory (Markdown source, shown as plain text).
### 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](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.
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`.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/fastify/fastify-static/security/advisories/GHSA-83w8-p2f5-377r
- https://nvd.nist.gov/vuln/detail/CVE-2026-15074
- https://github.com/fastify/fastify-static/commit/db4276f846ba56b21f93768cd6636ee5e2fc58b1
- https://cna.openjsf.org/security-advisories.html
- https://github.com/fastify/fastify-static
- https://github.com/fastify/fastify-static/releases/tag/v10.1.1