CVE-2026-14198

EIP tracks 1 public exploit for CVE-2026-14198. PoCs published by HermesNA-1.

AI-analyzed exploit summary This repository contains an auto-generated stub module for CVE-2026-14198, a path normalization vulnerability in @fastify/middie versions 9.1.0 through 9.3.2. The module includes placeholder code for probing targets but lacks actual exploit implementation, referencing external advisories for details.

@fastify/middie versions 9.1.0 through 9.3.2 decode the encoded slash %2F inside path parameter values before matching middleware paths, while Fastify's underlying router preserves the encoding during route lookup. The two layers disagree on the canonical request path, so the middleware fails to match a URL that the route handler does match. When middleware is used for authentication, authorization, rate limiting, or auditing on parameterized paths, an attacker can reach the protected handler by sending a single crafted URL with an encoded slash in the parameter position. The bypass is HTTP method agnostic and requires no authentication or special preconditions. Patches: upgrade to @fastify/middie 9.3.3. Workarounds: avoid parameterized middleware paths for security decisions, or enforce authentication at the route handler or via a Fastify hook that runs after the router has resolved the request.