cvedb.io
CVE-2026-66731
HIGH · CVSS 7.5
EPSS exploitation probability: 0%
Published 2026-07-27T17:16:42.793 · Last modified 2026-07-27T18:17:02.560

Summary

facil.io 0.7.5 through 0.7.6 contains a denial-of-service vulnerability in the HTTP/1.1 chunked transfer encoding parser that allows unauthenticated remote attackers to crash the server by sending a negative chunk size value. Attackers can send a single POST request with a Transfer-Encoding: chunked header containing a leading minus sign in the chunk size field, causing the parser in http1_parser.h to compute a large positive integer from the negated value, corrupting internal state and moving the read pointer into unmapped memory resulting in a fault.

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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.