cvedb.io
CVE-2026-55851
UNKNOWN · CVSS n/a
EPSS exploitation probability: 0%
Published 2026-07-21T22:17:14.340 · Last modified 2026-07-21T22:17:14.340

Summary

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final up to (but not including) 4.2.16.Final, and 4.1.0.Final up to (but not including) 4.1.135, the `HAProxyMessageDecoder` in Netty's `codec-haproxy` module performs protocol version detection by reading the 13th byte as a signed Java `byte` and widening it to `int` without masking; a PROXY protocol v2 binary prefix followed by version byte `0xFF` sign-extends to `-1`, collides with the decoder's need-more-data sentinel, and causes `ByteToMessageDecoder` to accumulate inbound bytes in an unbounded `cumulation` buffer until direct memory is exhausted. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

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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.