CVE-2026-15074 @fastify/static vulnerable to route guard bypass via path traversal
An unauthenticated attacker can bypass route guards to read files within the static root directory using dot-dot path segments.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-15074?
CVE-2026-15074 is a high-severity path traversal vulnerability in @fastify/static, published on 23 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
@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.
Weakness: CWE-22
Which versions are affected by CVE-2026-15074?
2 open source packages ship an affected version, including @fastify/static. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@fastify/static npm | All versions | 10.1.1 |
@fastify/static npm | All versions | 10.1.1 |
Products include Fastify Fastify-Static.
How do I fix CVE-2026-15074?
Upgrade @fastify/static to 10.1.1 or later.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-15074 being exploited?
There is no known exploitation of CVE-2026-15074 in the wild and no public exploit code.
Other vulnerabilities in @fastify/static
- CVE-2021-22964 DOS and Open Redirect with user input
- CVE-2026-18427 @fastify/static vulnerable to route guard bypass via non-canonical path segments
- CVE-2021-22963 URL Redirection to Untrusted Site ('Open Redirect') in fastify-static
- CVE-2026-6414 @fastify/static vulnerable to route guard bypass via encoded path separators
- CVE-2026-7120 @fastify/static vulnerable to Authorization Bypass via Non-Canonical URL Paths
Sources
Also known as GHSA-83w8-p2f5-377r, MINI-p3xf-68hm-jf7r.