CVE-2026-129122

Name	CVE-2026-129122
Description	C-Kermit 6.0.192 before 11.1.515 contains a buffer overflow vulnerability in tn_snenv() in ckctel.c that allows malicious Telnet servers to corrupt client memory via crafted NEW-ENVIRON SEND subnegotiation. Malicious or machine-in-the-middle servers can send oversized variable names before authentication, overflowing a 16-byte stack buffer and a miscomputed heap buffer to corrupt stack and heap memory.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
ckermit (PTS)	bookworm	402~beta08-1	vulnerable
	trixie	416~beta12-1+deb13u1	vulnerable
	forky	1:11.1.515-2	fixed
	sid	1:11.1.517-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
ckermit	source	(unstable)	1:11.1.515-1

Notes

[trixie] - ckermit <no-dsa> (Minor issue)
https://github.com/OpenKermit/ckermit/security/advisories/GHSA-c5px-7h4c-gj8p
Fixed by: https://github.com/OpenKermit/ckermit/commit/39ab009a365b97632e9975e1266fa618c4bdc59f (v11.1.515)
Fixed by: https://github.com/OpenKermit/ckermit/commit/42cf6decb926f56d606a76262791aaf071955d25 (v11.1.515)