cvedb.io
CVE-2026-56123
HIGH · CVSS 8.1
EPSS exploitation probability: 0%
Published 2026-06-25T17:17:01.967 · Last modified 2026-06-26T16:50:16.103

Summary

socat versions 1.8.0.0 through 1.8.1.1 contain a heap-based buffer overflow vulnerability that allows a malicious SOCKS5 proxy server to overwrite adjacent heap memory by exploiting a sign-extension flaw in the DOMAINNAME reply parser. During connection setup, the domain name length byte is read through a signed char field causing a negative bytes_to_read value that is implicitly converted to size_t, resulting in an unbounded heap write into the 262-byte reply buffer with attacker-controlled size and content.

Affected products

dest-unreach — socat

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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.