NVD security advisoryHigh
High advisory for netrek-client-cow
CVE-2026-121969 · Reported 4 Nov 2026
Full advisory details, affected packages, severity context, and original source.
Affected technology
netrek-client-cowAffected product
Advisory overview
netrek-client-cow through 3.3.3 contains a stack-based buffer overflow vulnerability in handleSMessage() in short.c that allows malicious servers to overflow a 100-byte stack buffer by sending oversized SP_S_MESSAGE packets. A malicious Netrek server or man-in-the-middle on the plaintext TCP connection can send overlong or unterminated message bodies to write server-controlled bytes onto the stack and crash the client.
Related references
- https://github.com/quozl/netrek-client-cow
- https://github.com/quozl/netrek-client-cow/blob/3.3.3/short.c#L949
- https://github.com/quozl/netrek-client-cow/commit/fb322e74abee3b0b76a9c5a31df6aab5585d3127
- https://github.com/quozl/netrek-client-cow/issues/11
- https://www.vulncheck.com/advisories/netrek-client-cow-through-3.3.3-stack-buffer-overflow-via-handlesmessage