CVE-2026-7120

@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate path separators in the pathname used for file resolution. Versions up to and including 10.1.1 are affected. An unauthenticated attacker can bypass allowedPath restrictions by requesting equivalent non-canonical pathnames, causing files that were intended to be denied to be served anyway. The bypass does not allow access outside the configured static root by itself, it defeats path-based filtering only. The issue is patched in @fastify/static 10.1.2.

@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate path separators in the pathname used for file resolution. Versions up to and including 10.1.1 are affected. An unauthenticated attacker can bypass allowedPath restrictions by requesting equivalent non-canonical pathnames, causing files that were intended to be denied to be served anyway. The bypass does not allow access outside the configured static root by itself, it defeats path-based filtering only. The issue is patched in @fastify/static 10.1.2.

Impact

@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate slashes in the pathname used for file resolution. Non-canonical pathnames such as //file, /./file, or /public/../private/file bypass allowedPath filtering while resolving to the intended file on disk.

Applications that use allowedPath as a security boundary to restrict access to specific static files or path subtrees may unintentionally expose files that were intended to be denied.

Patches

Upgrade to @fastify/static >= 10.1.2.

Workarounds

None. Upgrade to the patched version.

@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate path separators in the pathname used for file resolution. Versions up to and including 10.1.1 are affected. An unauthenticated attacker can bypass allowedPath restrictions by requesting equivalent non-canonical pathnames, causing files that were intended to be denied to be served anyway. The bypass does not allow access outside the configured static root by itself, it defeats path-based filtering only. The issue is patched in @fastify/static 10.1.2.

@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate path separators in the pathname used for file resolution. Versions up to and including 10.1.1 are affected. An unauthenticated attacker can bypass allowedPath restrictions by requesting equivalent non-canonical pathnames, causing files that were intended to be denied to be served anyway. The bypass does not allow access outside the configured static root by itself, it defeats path-based filtering only. The issue is patched in @fastify/static 10.1.2.

Impact

@fastify/static evaluates the allowedPath callback before normalizing dot segments and duplicate slashes in the pathname used for file resolution. Non-canonical pathnames such as //file, /./file, or /public/../private/file bypass allowedPath filtering while resolving to the intended file on disk.

Applications that use allowedPath as a security boundary to restrict access to specific static files or path subtrees may unintentionally expose files that were intended to be denied.

Patches

Upgrade to @fastify/static >= 10.1.2.

Workarounds

None. Upgrade to the patched version.