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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Red Hat Red Hat Enterprise Linux 10
Default version status: affected
0:6.4.38-3.el10_2.1 to < *unaffected
Red Hat Red Hat Enterprise Linux 8
Default version status: affected
0:6.4.24-1.el8_10.1 to < *unaffected
Red Hat Red Hat Enterprise Linux 9
Default version status: affected
0:6.4.24-1.el9_8.1 to < *unaffected
Red Hat Red Hat Enterprise Linux 6
Default version status: affected
Red Hat Red Hat Enterprise Linux 7
Default version status: affected
References
- https://access.redhat.com/errata/RHSA-2026:85959 ↗
- https://access.redhat.com/errata/RHSA-2026:86981 ↗
- https://access.redhat.com/errata/RHSA-2026:86982 ↗
- https://access.redhat.com/security/cve/CVE-2026-94184 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2531984 ↗
- https://bugzilla.redhat.com/show_bug.cgi?id=2537395 ↗
- https://gitlab.com/fetchmail/fetchmail/-/commit/cb5be5c38471eec19e519ace0bc569176317ea92 ↗
- https://www.fetchmail.info/fetchmail-SA-2026-01.txt ↗
- https://www.openwall.com/lists/oss-security/2026/06/27/8 ↗
- http://www.openwall.com/lists/oss-security/2026/09/23/1 ↗