@fastify/static vulnerable to route guard bypass via encoded path separators

Impact @fastify/static v9.1.0 and earlier decodes percent-encoded path separators %2F before filesystem resolution, but Fastify's router treats them as literal characters. This creates a routing mismatch: route guards on /admin/ do not match /admin%2Fsecret.html, but @fastify/static decodes it to...

CVE-2026-6414

A flaw was found in @fastify/static. A remote attacker can exploit this vulnerability by sending specially crafted requests that include percent-encoded path separators. This mismatch in how @fastify/static decodes these separators compared to the Fastify router allows the attacker to bypass...

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

@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. F...

PT-2026-33313

Name of the Vulnerable Software and Affected Versions @fastify/static versions 8.0.0 through 9.1.0 Description @fastify/static decodes percent-encoded path separators '%2F' before filesystem resolution, whereas the Fastify router treats them as literal characters. This discrepancy allows for a...