Intel

AIKIDO-2026-221297

@fastify/static is vulnerable to Path Traversal

Path TraversalCVE-2026-18427 Published Yesterday

75

High Risk

This Affects:

JS@fastify/static
0.0.1 - 10.1.2
Fixed in 10.1.3
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TL;DR

@fastify/static is vulnerable to a bypass of route-based middleware and guards via non-canonical . and // path segments. This lets an unauthenticated request read files in the static root that a route guard was meant to protect, defeating route-level authorization. The fix canonicalizes the pathname used for routing and serving, including rejecting backslashes.

Who does this affect?

You are affected if you are using a version that falls within the vulnerable range and you rely on route-based middleware or guards to protect files served by @fastify/static.

Background info

@fastify/static is vulnerable to Path Traversal in versions 0.0.1 - 10.1.2.

How to fix this

Upgrade the @fastify/static library to the patch version.