CVE-2026-7120: @fastify/static vulnerable to Authorization Bypass via Non-Canonical URL Paths
@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.
Other sources
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.
— GitHub
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/@fastify/staticto a version that resolves this vulnerability.Fixed in 10.1.2 - Upgrade
Upgrade
@fastify/staticto a version that resolves this vulnerability.Fixed in 10.1.2
Event History
Frequently Asked Questions
What is the severity of CVE-2026-7120?
CVE-2026-7120 has a medium severity score of 5.3.
How do I fix CVE-2026-7120?
To fix CVE-2026-7120, upgrade @fastify/static to version 10.1.2 or later.
What does CVE-2026-7120 affect?
CVE-2026-7120 affects versions of @fastify/static up to and including 10.1.1.
What type of vulnerability is CVE-2026-7120?
CVE-2026-7120 is an authorization bypass vulnerability via non-canonical URL paths.
Who can exploit CVE-2026-7120?
CVE-2026-7120 can be exploited by unauthenticated attackers.