CVE-2026-85184
An unauthenticated network attacker can use this to bypass path-based access controls in a Fastify application that relies on middie for those controls.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.52%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 0.52% probability · 44th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-436
- Affected
- fastify/fastify\/middie
- Source
- ce714d77-add3-4f53-aff5-83d477b104bb
EPSS 0.5% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://cna.openjsf.org/security-advisories.htmlThird Party Advisory
- https://github.com/fastify/middie/security/advisories/GHSA-hx87-8wv7-pjv8Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.