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.
Metrics
CVSS 3.1 9.1/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:NWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| @fastify/middie | @fastify/middie | < 9.3.2 |
References
- https://cna.openjsf.org/security-advisories.htmlVendor Advisory
- https://github.com/fastify/fastify-express/security/advisories/GHSA-hrwm-hgmj-7p9cExploit, Mitigation, Vendor Advisory
- https://github.com/fastify/middie/security/advisories/GHSA-72c6-fx6q-fr5wVendor Advisory
Timeline
- Published
- Apr 16, 2026
- Last modified
- Jun 17, 2026
- NVD status
- Analyzed