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...

@fastify/express security vulnerability

@fastify/express is a compatibility plugin developed by Fastify. Versions of @fastify/express 4.0.4 and earlier contain security vulnerabilities. These vulnerabilities stem from errors in path handling within the onRegister function, which cause the middleware paths to be added repeatedly when...

@fastify/express security vulnerability

@fastify/express is a compatibility plugin developed by Fastify. Versions of @fastify/express 4.0.4 and earlier contain security vulnerabilities. These vulnerabilities arise from failing to normalize URLs before passing them to Express middleware when the Fastify router normalization option is...

CVE-2026-33807: Interpretation Conflict

@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,...

CVE-2026-33808: Interpretation Conflict

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...

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...

CVE-2026-22037

The @fastify/express plugin adds full Express compatibility to Fastify. A security vulnerability exists in @fastify/express prior to version 4.0.3 where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of /admin. While the...

GHSA-G6Q3-96CP-5R5M @fastify/express vulnerable to Improper Handling of URL Encoding (Hex Encoding)

Summary A security vulnerability exists in @fastify/express where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of /admin. While the middleware engine fails to match the encoded path and skips execution, the underlying Fastif...

@cmmn/tools (>=3.0.0-alpha-1, <=3.0.0-alpha-6), mikr0 (0.1.10) potentially affected by CVE-2026-22037 via @fastify/express (>=4.0.1, <=4.0.2)

@fastify/express NPM version =4.0.1, =3.0.0-alpha-1, =3.0.0-alpha-6 - mikr0 0.1.10 Source cves: CVE-2026-22037 Source advisory: OSV:GHSA-G6Q3-96CP-5R5M...

@cmmn/tools (>=3.0.0-alpha-1, <=3.0.0-alpha-6), mikr0 (0.1.10) potentially affected by CVE-2026-22037 via @fastify/express (>=4.0.1, <=4.0.2)

@fastify/express NPM version =4.0.1, =3.0.0-alpha-1, =3.0.0-alpha-6 - mikr0 0.1.10 Source cves: CVE-2026-22037 Source advisory: GHSA-G6Q3-96CP-5R5M...

@fastify/express vulnerable to Improper Handling of URL Encoding (Hex Encoding)

Summary A security vulnerability exists in @fastify/express where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of /admin. While the middleware engine fails to match the encoded path and skips execution, the underlying Fastif...

Improper Handling of URL Encoding (Hex Encoding)

Overview @fastify/express is an Express compatibility layer for Fastify Affected versions of this package are vulnerable to Improper Handling of URL Encoding Hex Encoding where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of...

@cmmn/tools (>=3.0.0-alpha-1, <=3.0.0-alpha-6), mikr0 (0.1.10) potentially affected by CVE-2026-22037 via @fastify/express (>=4.0.1, <=4.0.2)

@fastify/express NPM version =4.0.1, =3.0.0-alpha-1, =3.0.0-alpha-6 - mikr0 0.1.10 Source cves: CVE-2026-22037 Source advisory: SNYK:JS-FASTIFYEXPRESS-15038741...

CVE-2026-22037

The @fastify/express plugin adds full Express compatibility to Fastify. A security vulnerability exists in @fastify/express prior to version 4.0.3 where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of /admin. While the...

CVE-2026-22037

The @fastify/express plugin adds full Express compatibility to Fastify. A security vulnerability exists in @fastify/express prior to version 4.0.3 where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., "/%61dmin" instead of "/admin". While the...

CVE-2026-22037 @fastify/express vulnerable to Improper Handling of URL Encoding (Hex Encoding)

The @fastify/express plugin adds full Express compatibility to Fastify. A security vulnerability exists in @fastify/express prior to version 4.0.3 where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of /admin. While the...

CVE-2026-22037

The vulnerability affects the @fastify/express plugin (prior to version 4.0.3). Middleware registered for a specific path prefix can be bypassed when the request uses URL-encoded characters (e.g., /%61dmin instead of /admin). The middleware engine fails to match the encoded path, but the underlyi...

CVE-2026-22037 @fastify/express vulnerable to Improper Handling of URL Encoding (Hex Encoding)

The @fastify/express plugin adds full Express compatibility to Fastify. A security vulnerability exists in @fastify/express prior to version 4.0.3 where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of /admin. While the...

@adbl/cartridge (>=0.0.3, <=0.0.5), @agrume/cli (3.0.0) +31 more potentially affected by CVE-2026-22037 via @fastify/express (>=1.1.0, <=4.0.2)

@fastify/express NPM version =1.1.0, =0.0.3, =2.0.0-beta.0, =8.0.0, =3.0.0-alpha-1, =0.29.0, =1.0.0-alpha.1, =1.0.0-beta-cloud-customizer.1, =1.0.0, =0.0.0-canary-20250922152503, =0.0.0-canary-20250922152503, =0.0.0-canary-20251023225836, =2.4.1-beta.1, =1.0.0, =1.6.0 and more Source cves:...

CVE-2026-22037

The @fastify/express plugin adds full Express compatibility to Fastify. A security vulnerability exists in @fastify/express prior to version 4.0.3 where middleware registered with a specific path prefix can be bypassed using URL-encoded characters e.g., /%61dmin instead of /admin. While the...