@fastify/middie versions >= 9.1.0 and before 9.3.4 decide whether to run path-scoped middleware by matching against the raw request target, while the Fastify router resolves an absolute-form request target to its path before dispatching. Because the two layers evaluate different strings, a request using an absolute-form target reaches the route handler while the path-scoped middleware, such as authentication or authorization, is skipped. An unauthenticated network attacker can use this to bypass path-based access controls in a Fastify application that relies on middie for those controls. Users should upgrade to @fastify/middie 9.3.4 or later.
Metrics
Affected Vendors & Products
References
History
Sat, 05 Sep 2026 22:30:00 +0000
| Type | Values Removed | Values Added |
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| Metrics |
ssvc
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Fri, 04 Sep 2026 14:30:00 +0000
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| First Time appeared |
Fastify
Fastify fastify/middie |
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| Vendors & Products |
Fastify
Fastify fastify/middie |
Fri, 04 Sep 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | @fastify/middie versions >= 9.1.0 and before 9.3.4 decide whether to run path-scoped middleware by matching against the raw request target, while the Fastify router resolves an absolute-form request target to its path before dispatching. Because the two layers evaluate different strings, a request using an absolute-form target reaches the route handler while the path-scoped middleware, such as authentication or authorization, is skipped. An unauthenticated network attacker can use this to bypass path-based access controls in a Fastify application that relies on middie for those controls. Users should upgrade to @fastify/middie 9.3.4 or later. | |
| Title | @fastify/middie vulnerable to path-scoped middleware bypass via absolute-form request target | |
| Weaknesses | CWE-436 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: openjs
Published: 2026-09-04T09:15:51.216Z
Updated: 2026-09-04T19:36:20.968Z
Reserved: 2026-09-03T11:39:08.481Z
Link: CVE-2026-85184
Updated: 2026-09-04T19:36:17.234Z
Status : Awaiting Analysis
Published: 2026-09-04T10:17:13.900
Modified: 2026-09-08T19:07:52.113
Link: CVE-2026-85184
No data.