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CVE-2026-33807criticalCWE-436

@fastify/express vulnerable to middleware path doubling causing authentication bypass in child plugin scopes

28Vexday Risk Score

Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.

ssvc Trackcvss 9.1epss 0.4%
probabilidad de explotación
0.4%top 65% de las CVE
explotación observada
noninguna fuente lo reporta
@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. Upgrade to @fastify/express v4.0.5 or later.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Productos afectados
fastify · @fastify/express