Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

CVE-2026-33807

Gravedad CVSS v3.1:
CRÍTICA
Tipo:
No Disponible / Otro tipo
Fecha de publicación:
15/04/2026
Última modificación:
17/04/2026

Descripción

*** Pendiente de traducción *** @fastify/express v4.0.4 and earlier contains a path handling bug in the onRegister function that causes middleware paths to be doubled when inherited by child plugins. When a child plugin is registered with a prefix that matches a middleware path, the middleware path is prefixed a second time, causing it to never match incoming requests. This results in complete bypass of Express middleware security controls, including authentication, authorization, and rate limiting, for all routes defined within affected child plugin scopes. No special configuration or request crafting is required.<br /> <br /> Upgrade to @fastify/express v4.0.5 or later.