EUVD-2026-23235

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

@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...

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...

CVE-2026-33804

@fastify/middie versions 9.3.1 and earlier are vulnerable to middleware bypass when the deprecated Fastify ignoreDuplicateSlashes option is enabled. The middleware path matching logic does not account for duplicate slash normalization performed by Fastify's router, allowing requests with duplicat...

CVE-2026-33804

CVE-2026-33804 affects @fastify/middie v9.3.1 and earlier, where middleware bypass can occur when the deprecated top-level ignoreDuplicateSlashes option is enabled. The middleware’s path-matching does not account for duplicate-slash normalization performed by Fastify’s router, allowing requests w...

CVE-2026-33804 @fastify/middie vulnerable to middleware bypass via deprecated ignoreDuplicateSlashes option

@fastify/middie versions 9.3.1 and earlier are vulnerable to middleware bypass when the deprecated Fastify ignoreDuplicateSlashes option is enabled. The middleware path matching logic does not account for duplicate slash normalization performed by Fastify's router, allowing requests with duplicat...

CVE-2026-33804

@fastify/middie versions 9.3.1 and earlier are vulnerable to middleware bypass when the deprecated Fastify ignoreDuplicateSlashes option is enabled. The middleware path matching logic does not account for duplicate slash normalization performed by Fastify's router, allowing requests with duplicat...

CVE-2026-33804 @fastify/middie vulnerable to middleware bypass via deprecated ignoreDuplicateSlashes option

@fastify/middie versions 9.3.1 and earlier are vulnerable to middleware bypass when the deprecated Fastify ignoreDuplicateSlashes option is enabled. The middleware path matching logic does not account for duplicate slash normalization performed by Fastify's router, allowing requests with duplicat...

@fastify/express has a middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons)

Summary @fastify/express v4.0.4 fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via two vectors: 1. Duplicate slashes //admin/dashboard when...

GHSA-6HW5-45GM-FJ88 @fastify/express has a middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons)

Summary @fastify/express v4.0.4 fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via two vectors: 1. Duplicate slashes //admin/dashboard when...

PT-2026-33323

Name of the Vulnerable Software and Affected Versions @fastify/middie versions prior to 9.3.2 Description A middleware bypass exists when the deprecated ignoreDuplicateSlashes option is enabled. The middleware path matching logic fails to account for duplicate slash normalization performed by the...

@fastify/middie 安全漏洞

@fastify/middie is an open-source middleware engine developed by Fastify. Versions of @fastify/middie 9.3.1 and earlier contained security vulnerabilities. These vulnerabilities occurred when the deprecated ignoreDuplicateSlashes option was enabled, as the middleware’s path matching logic did not...

Interpretation Conflict

Overview @fastify/express is an Express compatibility layer for Fastify Affected versions of this package are vulnerable to Interpretation Conflict via improper URL normalization gaps. An attacker can gain unauthorized access to protected routes by manipulating the URL path with duplicate slashes...

CVE-2026-33808 @fastify/express vulnerable to middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons)

Impact@fastify/express v4.0.4 and earlier fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via duplicate slashes when ignoreDuplicateSlashes is enabled, or...

CVE-2026-33808

Impact@fastify/express v4.0.4 and earlier fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via duplicate slashes when ignoreDuplicateSlashes is enabled, or...

CVE-2026-33808 @fastify/express vulnerable to middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons)

Impact@fastify/express v4.0.4 and earlier fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows complete bypass of path-scoped authentication middleware via duplicate slashes when ignoreDuplicateSlashes is enabled, or...

CVE-2026-33808

CVE-2026-33808 affects fastify/express. Root cause: @fastify/express v4.0.4 and earlier fail to normalize URLs before passing to Express middleware when Fastify router normalization is enabled, allowing bypass of path-scoped authentication via duplicate slashes or semicolon delimiters. Outcome: a...

PT-2026-33035

Name of the Vulnerable Software and Affected Versions @fastify/express versions prior to 4.0.5 Description An issue exists where the software fails to normalize URLs before passing them to Express middleware when Fastify router normalization options are enabled. This allows an unauthenticated...

EUVD-2026-9049

@fastify/middie has Improper Path Normalization when Using Path-Scoped Middleware...

Interpretation Conflict

Overview @fastify/middie is a Middleware engine for Fastify Affected versions of this package are vulnerable to Interpretation Conflict via the middleware matching engine when router options like ignoreDuplicateSlashes, useSemicolonDelimiter, or other trailing-slash normalization are enabled. An...