VULNERABILITY INTELLIGENCE

CVE-2026-6270

CVSS score9.1 CRITICAL
EPSS probability0.50%
CISA KEVNot currently listed
Published2026-04-16
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Description

@fastify/middie versions 9.3.1 and earlier do not register inherited middleware directly on child plugin engine instances. When a Fastify application registers authentication middleware in a parent scope and then registers child plugins with @fastify/middie, the child scope does not inherit the parent middleware. This allows unauthenticated requests to reach routes defined in child plugin scopes, bypassing authentication and authorization checks. Upgrade to @fastify/middie 9.3.2 to fix this issue. There are no workarounds.

Weakness classification

  • ce714d77-add3-4f53-aff5-83d477b104bb: CWE-436

Primary references