p PatchFirst

CVE-2026-6414

CVE-2026-6414 · @fastify/static vulnerable to route guard bypass via encoded path separators

This page contains facts from public vulnerability sources. Check the original advisory before updating.

@fastify/static versions 8.0.0 through 9.1.0 decode percent-encoded path separators (%2F) before filesystem resolution, while Fastify's router treats them as literal characters. This mismatch allows attackers to bypass route-based middleware or guards that protect files served by @fastify/static. For example, a route guard on a protected path can be circumvented by encoding the path separator in the URL. Upgrade to @fastify/static 9.1.1 to fix this issue. There are no workarounds.

CVSS 5.9 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: node

Affected products and versions

  • @fastify/static

    Versions
    • ≥ 8.0.0, < 9.1.1: Affected (semver)
    • 9.1.1: Not affected (semver)

    Update to 9.1.1

  • @fastify/static npm

    Affected ranges
    • SEMVER: ≥ 8.0.0, < 9.1.1

    Update to 9.1.1

Original sources

Check your server →