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TI-2026-63367 Aliases CVE-2026-94184GHSA-5pfw-5pv2-2pc6

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

Priority MEDIUM 40CWE-121Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 3 fixed, 2 without a fix

Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-121 and the CVSS impact.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01195 68th percentileScored 2026-11-07
Fix Partial Red Hat: 3 advisoriesRed Hat: 3 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red HatRed Hat Enterprise Linux 10—6.4.38-3.el10_2.1Patch availableCNA
Red HatRed Hat Enterprise Linux 8—6.4.24-1.el8_10.1Patch availableCNA
Red HatRed Hat Enterprise Linux 9—6.4.24-1.el9_8.1Patch availableCNA
Red HatRed Hat Enterprise Linux 6——No fix listedCNA
Red HatRed Hat Enterprise Linux 7——No fix listedCNA
  • Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in 6.4.38-3.el10_2.1 Patch available CNA
  • Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in 6.4.24-1.el8_10.1 Patch available CNA
  • Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in 6.4.24-1.el9_8.1 Patch available CNA
  • Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE names CNA · 5

CPEVersionsRoleVendor
cpe:/o:redhat:enterprise_linux:10.210.2—Red Hat
cpe:/a:redhat:enterprise_linux:8::appstream8—Red Hat
cpe:/a:redhat:enterprise_linux:9::appstream9—Red Hat
cpe:/o:redhat:rhel_els:66—Red Hat
cpe:/o:redhat:rhel_els:77—Red Hat
  • cpe:/o:redhat:enterprise_linux:10.2 Versions 10.2 — ·Red Hat
  • cpe:/a:redhat:enterprise_linux:8::appstream Versions 8 — ·Red Hat
  • cpe:/a:redhat:enterprise_linux:9::appstream Versions 9 — ·Red Hat
  • cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
  • cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat

Remediation

Red Hat 3 advisories

  • RHSA-2026:86981 Released 2026-10-21 · Red Hat rating Moderate
    fetchmail security update
    • Red Hat Enterprise Linux AppStream (v. 9) fetchmail-6.4.24-1.el9_8.1
  • RHSA-2026:86982 Released 2026-10-21 · Red Hat rating Moderate
    fetchmail security update
    • Red Hat Enterprise Linux AppStream (v. 8) fetchmail-6.4.24-1.el8_10.1
  • RHSA-2026:85959 Released 2026-10-20 · Red Hat rating Moderate
    fetchmail security update
    • Red Hat Enterprise Linux AppStream (v. 10) fetchmail-6.4.38-3.el10_2.1

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:85959
Red Hat Enterprise Linux AppStream (v. 8)Fixed RHSA-2026:86982
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:86981

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-94184
  2. 2026-10-03 Alias added: GHSA-5pfw-5pv2-2pc6
  3. 2026-10-20 Fix available: fetchmail@0:6.4.38-3.el10_2.1 · CNA
  4. 2026-10-20 1 new reference · CNA
  5. 2026-10-20 Fix available: RHSA-2026:85959 · Red Hat
  6. 2026-10-21 Fix available: Red Hat Enterprise Linux AppStream (v. 10) · Red Hat
  7. 2026-10-21 Fix available: fetchmail@0:6.4.24-1.el8_10.1 · CNA
  8. 2026-10-21 1 new reference · CNA
  9. 2026-10-21 Fix available: fetchmail@0:6.4.24-1.el9_8.1 · CNA
  10. 2026-10-21 1 new reference · CNA
  11. 2026-10-21 Fix available: RHSA-2026:86982 · Red Hat
  12. 2026-10-21 Fix available: RHSA-2026:86981 · Red Hat
  13. 2026-10-21 Fix available: Red Hat Enterprise Linux AppStream (v. 8), Red Hat Enterprise Linux AppStream (v. 9) · Red Hat
  14. 2026-10-25 Priority changed: LOW → MEDIUM

References

Advisory 3

Other 6

  • TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
See all 7413 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences