cvedb.io
CVE-2026-14181
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-07-01T12:16:38.343 · Last modified 2026-07-02T13:50:58.743

Summary

@fastify/middie versions 9.1.0 through 9.3.2 fail to guard the URL normalization step used by the standalone engine when incoming request paths contain malformed percent-encoded sequences. Inputs such as an incomplete percent escape or a truncated multibyte sequence cause the underlying decoder to throw synchronously, and the exception escapes the middie normalize step and terminates the Node.js process. The bypass affects applications that call middie.run directly on the standalone engine API, causing an immediate denial of service for all connected clients until restart. Applications using the Fastify plugin path are not affected because Fastifys error handler catches the exception. Patches: upgrade to @fastify/middie 9.3.3. Workarounds: migrate from the standalone engine API to the Fast

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.