Interpretation Conflict

Overview @fastify/middie is a Middleware engine for Fastify Affected versions of this package are vulnerable to Interpretation Conflict in the resolveNormalizationOptions function's deprecated ignoreDuplicateSlashes configuration option. An attacker can bypass middleware by crafting URLs with...

GHSA-V9WW-2J6R-98Q6 @fastify/middie vulnerable to middleware bypass via deprecated ignoreDuplicateSlashes option

Impact @fastify/middie v9.3.1 and earlier does not read the deprecated but still functional top-level ignoreDuplicateSlashes option, only reading from routerOptions. This creates a normalization gap: Fastify's router normalizes duplicate slashes but middie does not, allowing middleware bypass via...

@fastify/middie vulnerable to middleware bypass via deprecated ignoreDuplicateSlashes option

Impact @fastify/middie v9.3.1 and earlier does not read the deprecated but still functional top-level ignoreDuplicateSlashes option, only reading from routerOptions. This creates a normalization gap: Fastify's router normalizes duplicate slashes but middie does not, allowing middleware bypass via...

CVE-2026-2880 @fastify/middie has an improper path normalization vulnerability

A vulnerability in @fastify/middie versions 9.2.0 can result in authentication/authorization bypass when using path-scoped middleware for example, app.use'/secret', auth. When Fastify router normalization options are enabled such as ignoreDuplicateSlashes, useSemicolonDelimiter, and related...

CVE-2026-2880 @fastify/middie has an improper path normalization vulnerability

A vulnerability in @fastify/middie versions 9.2.0 can result in authentication/authorization bypass when using path-scoped middleware for example, app.use'/secret', auth. When Fastify router normalization options are enabled such as ignoreDuplicateSlashes, useSemicolonDelimiter, and related...