CVE-2026-94184

Name	CVE-2026-94184
Description	A stack-based buffer overflow flaw was found in fetchmail when built with NTLM support. A malicious or compromised mail server advertising NTLM authentication can send a crafted Type 2 challenge that causes fetchmail to write past a fixed stack buffer while building the NTLM authenticate response. This may lead to remote code execution depending on stack-frame layout, or to authentication failure or process termination under memory hardening. Affects v5.0.8 through v6.6.6.
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
fetchmail (PTS)	bookworm	6.4.37-1	vulnerable
	trixie	6.4.39-1	vulnerable
	forky, sid	6.6.6-1	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
fetchmail	source	(unstable)	(unfixed)

Notes

[trixie] - fetchmail <no-dsa> (Minor issue)
https://www.fetchmail.info/fetchmail-SA-2026-01.txt
Fixed by: https://gitlab.com/fetchmail/fetchmail/-/commit/cb5be5c38471eec19e519ace0bc569176317ea92 (6.6.7.rc1)