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Fencer Vulns
high 8.1

CVE-2026-94184 json

Fetchmail: fetchmail: stack-based buffer overflow in ntlm authentication (fetchmail-sa-2026-01)

published 2026-09-21 49 d ago modified 2026-11-06 3 d ago also EUVD-2026-83923

cvss
8.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

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.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 10 0:6.4.38-3.el10_2.1
  • Red Hat Red Hat Enterprise Linux 8 0:6.4.24-1.el8_10.1
  • Red Hat Red Hat Enterprise Linux 9 0:6.4.24-1.el9_8.1
  • fetchmail Debian 14 6.6.8-1

debian advisories DEBIAN-CVE-2026-94184

  • fetchmail SLES for SAP applications 16.0, SLES 16.0 6.5.2-160000.4.1
  • fetchmail SLES for SAP 15 SP5, SLES for SAP 15 SP4, SLES 15 SP5-LTSS +5 more 6.4.22-150000.20.32.1
  • fetchmail SLES for SAP 15 SP6, SLES 15 SP6-LTSS, SLE Module for Desktop Applications 15 SP7 +1 more 6.4.22-150600.35.6.1
  • fetchmail SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 6.3.26-13.24.1

suse advisories SUSE-SU-2026:24221-1SUSE-SU-2026:4605-1SUSE-SU-2026:4604-1SUSE-SU-2026:4567-1

  • fetchmail openSUSE Tumbleweed 6.6.8-1.1
  • fetchmail openSUSE Leap 16.0 6.5.2-160000.4.1

opensuse advisories openSUSE-SU-2026:12115-1openSUSE-SU-2026:22077-1

  • fetchmail AlmaLinux 9 6.4.24-1.el9_8.1
  • fetchmail AlmaLinux 8 6.4.24-1.el8_10.1
  • fetchmail AlmaLinux 10 6.4.38-3.el10_2.1

almalinux advisories ALSA-2026:86981ALSA-2026:86982ALSA-2026:85959

  • fetchmail Rocky Linux 10 6.4.38-3.el10_2.1
  • fetchmail Rocky Linux 9 6.4.24-1.el9_8.1
  • fetchmail Rocky Linux 8 6.4.24-1.el8_10.1

rocky linux advisories RLSA-2026:85959RLSA-2026:86981RLSA-2026:86982

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-94184 updated cvss 5.3

fetchmail: fetchmail: stack-based buffer overflow in NTLM authentication (fetchmail-SA-2026-01)

  • Red Hat Enterprise Linux 6 fetchmail 6.3.17-1.el6 Red Hat Enterprise Linux 7 fetchmail 6.3.17-1.el6
    affected: workaround, no fix available “Rebuild fetchmail without --enable-NTLM (omit NTLM at configure time). Confirm with `fetchmail -V` that the build does not list +NTLM.”
  • Red Hat Enterprise Linux AppStream (v. 8) fetchmail 6.4.24-1.el8_10.1
    fixed: vendor fix “Rebuild fetchmail without --enable-NTLM (omit NTLM at configure time). Confirm with `fetchmail -V` that the build does not list +NTLM.” RHSA-2026:86982
  • Red Hat Enterprise Linux AppStream (v. 9) fetchmail 6.4.24-1.el9_8.1
    fixed: vendor fix “Rebuild fetchmail without --enable-NTLM (omit NTLM at configure time). Confirm with `fetchmail -V` that the build does not list +NTLM.” RHSA-2026:86981
  • Red Hat Enterprise Linux AppStream (v. 10) fetchmail 6.4.38-3.el10_2.1
    fixed: vendor fix “Rebuild fetchmail without --enable-NTLM (omit NTLM at configure time). Confirm with `fetchmail -V` that the build does not list +NTLM.” RHSA-2026:85959

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
48 d ago

Exploit prediction

1.20% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CISA ADP 3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA 3.1 8.1 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 10
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7

Classification

Weakness
  • CWE-121 Stack-based Buffer Overflow

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.