Vulnerability · Published Jul 23, 2026 · Assigned by openjs
CVE-2026-15074@fastify/static vulnerable to route guard bypass via path traversal
High 7.5
In plain English
A high-severity path traversal in @fastify/static from @fastify/static. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @fastify/static | 10.1.1 | GHSA-83w8-p2f5-377r |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| @fastify/static | @fastify/static | 0 – before 10.1.1 |
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N