CVE-2026-15074
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk37th percentile - higher than 37% of all known CVEs
Summary
The @fastify/static library up to version 10.1.0 fails to reject '..' path segments before file resolution. This allows bypassing path traversal protections and reading files inside the static root that are under a guarded URL prefix. The issue is patched in version 10.1.1.
Risk Assessment
An unauthenticated attacker can bypass route middleware and read static files that should be protected, potentially leading to sensitive data disclosure.
Recommendation
Upgrade @fastify/static to version 10.1.1 or later.
Other vulnerabilities in @fastify/static
See all- CVE-2026-18427High
@fastify/static before version 10.1.3 contains an incomplete fix for a previous route guard bypass. The static file handler rejected only parent directory segments, but it did not canonicalize dot segments, duplicate slashes, encoded dots, or backslashes before route matching and before delegating to the send layer. As a result, an unauthenticated attacker could request a file protected by a route based guard using a non canonical path form that misses the guarded route yet resolves back onto the protected file, disclosing its contents. Applications that protect a subtree of the static root with a route based guard are affected, while applications relying on the allowedPath option are not. This is fixed in @fastify/static 10.1.3, which canonicalizes the pathname, including rejecting backslashes, on the path used for routing and serving.
- CVE-2026-7120Medium
In @fastify/static before version 10.1.2, the allowedPath callback is evaluated before normalizing dot segments and duplicate path separators. An unauthenticated attacker can bypass allowedPath restrictions by requesting non-canonical paths, allowing files intended to be denied to be served.
Original NVD description (English source)
@fastify/static up to and including version 10.1.0 fails to reject dot-dot path segments in request pathnames before the file-resolution stage. This is a bypass of the earlier fix for CVE-2026-6414, which only covered encoded forward slashes. Because the underlying send library normalizes dot segments before applying its own path-traversal guard, an unauthenticated attacker can bypass any route-scoped middleware and read files inside the static root that live under the guarded URL prefix. The bypass does not allow access outside the configured static root by itself, it defeats route-guard filtering only. The issue is patched in @fastify/static 10.1.1.