PatchesUpgrade to @fastify/express v4.0.5 or later.
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No vendor fix or workaround currently provided.
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Tracking
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| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-6hw5-45gm-fj88 | @fastify/express has a middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons) |
Wed, 15 Apr 2026 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Fastify
Fastify fastify-express |
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| Vendors & Products |
Fastify
Fastify fastify-express |
Wed, 15 Apr 2026 14:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Wed, 15 Apr 2026 10:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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 via semicolon delimiters when useSemicolonDelimiter is enabled. In both cases, Fastify router normalizes the URL and matches the route, but @fastify/express passes the original un-normalized URL to Express middleware, which fails to match and is skipped. An unauthenticated attacker can access protected routes by manipulating the URL path. PatchesUpgrade to @fastify/express v4.0.5 or later. | |
| Title | @fastify/express vulnerable to middleware authentication bypass via URL normalization gaps (duplicate slashes and semicolons) | |
| Weaknesses | CWE-436 | |
| References |
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| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: openjs
Published:
Updated: 2026-04-15T13:10:24.054Z
Reserved: 2026-03-23T19:48:48.715Z
Link: CVE-2026-33808
Updated: 2026-04-15T13:10:10.057Z
Status : Awaiting Analysis
Published: 2026-04-15T10:16:48.453
Modified: 2026-04-17T15:38:09.243
Link: CVE-2026-33808
No data.
OpenCVE Enrichment
Updated: 2026-04-15T14:53:06Z
Github GHSA