cvedb.io
CVE-2026-6270
CRITICAL · CVSS 9.1
EPSS exploitation probability: 0%
Published 2026-04-16T14:16:19.433 · Last modified 2026-06-17T11:00:34.460

Summary

@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.

Affected products

fastify — fastify\/middie

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.