CVE-2026-129126

Description

C-Kermit before 11.1.515 contains a heap buffer overflow vulnerability in putsrv() in ckcfns.c that allows malicious peers to write past the srvcmd buffer by sending crafted packets. Attackers can use Kermit repeat-count compression in server command, GET, or file-header packets to write attacker-chosen bytes beyond the heap buffer on servers or receiving instances.

References

• https://github.com/OpenKermit/ckermit/blob/v11.0.514/ckcfns.c#L461
• https://github.com/OpenKermit/ckermit/commit/37e54720779237897bc6887efac42fe138817897
• https://github.com/OpenKermit/ckermit/releases/tag/v11.1.515
• https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p
• https://www.vulncheck.com/advisories/c-kermit-before-11.1.515-heap-buffer-overflow-via-putsrv-packet-decoding