Fetchmail: fetchmail: stack-based buffer overflow in ntlm authentication (fetchmail-sa-2026-01)
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.1epss 0.4%
exploitation probability
0.4%top 68% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
Red Hat · Red Hat Enterprise Linux 10Red Hat · Red Hat Enterprise Linux 6Red Hat · Red Hat Enterprise Linux 7Red Hat · Red Hat Enterprise Linux 8Red Hat · Red Hat Enterprise Linux 9References
https://access.redhat.com/security/cve/CVE-2026-94184https://bugzilla.redhat.com/show_bug.cgi?id=2537395https://gitlab.com/fetchmail/fetchmail/-/commit/cb5be5c38471eec19e519ace0bc569176317ea92https://www.fetchmail.info/fetchmail-SA-2026-01.txthttps://www.openwall.com/lists/oss-security/2026/06/27/8http://www.openwall.com/lists/oss-security/2026/09/23/1