Vulnerability · Published Sep 21, 2026 · Assigned by redhat
CVE-2026-94184Fetchmail: fetchmail: stack-based buffer overflow in ntlm authentication (fetchmail-sa-2026-01)
Medium 5.3
In plain English
A medium-severity stack buffer overflow in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 68% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | fetchmail | 6.4.38-3.el10_2.1 | ALSA-2026:85959 |
| AlmaLinux:8 | fetchmail | 6.4.24-1.el8_10.1 | ALSA-2026:86982 |
| AlmaLinux:9 | fetchmail | 6.4.24-1.el9_8.1 | ALSA-2026:86981 |
| Debian:12 | fetchmail | no fix listed | DEBIAN-CVE-2026-94184 |
| Debian:13 | fetchmail | no fix listed | DEBIAN-CVE-2026-94184 |
| Debian:14 | fetchmail | 6.6.8-1 | DEBIAN-CVE-2026-94184 |
| Rocky Linux:10 | fetchmail | 0:6.4.38-3.el10_2.1 | RLSA-2026:85959 |
| Rocky Linux:8 | fetchmail | 0:6.4.24-1.el8_10.1 | RLSA-2026:86982 |
| Rocky Linux:9 | fetchmail | 0:6.4.24-1.el9_8.1 | RLSA-2026:86981 |
| Ubuntu:22.04:LTS | fetchmail | no fix listed | UBUNTU-CVE-2026-94184 |
| Ubuntu:24.04:LTS | fetchmail | no fix listed | UBUNTU-CVE-2026-94184 |
| Ubuntu:26.04:LTS | fetchmail | no fix listed | UBUNTU-CVE-2026-94184 |
| Ubuntu:26.10 | fetchmail | no fix listed | UBUNTU-CVE-2026-94184 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
Weakness: CWE-121 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
References
- RHSA-2026:85959 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:86981 vendor-advisory, x_refsource_REDHAT
- RHSA-2026:86982 vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-94184 vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2531984
- RHBZ#2537395 issue-tracking, x_refsource_REDHAT
- 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