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mutt before 2.3.2 has a show_sig_summary NULL pointer dereference. (CVE-2026-43864)

0
Medium
VulnerabilityCVE-2026-43864gcveosvubuntu-cve-2026-43864cve-2026-43864ubuntu-pro-16-04-ltsubuntu-pro-18-04-ltsubuntu-20-04-ltsubuntu-22-04-ltsubuntu-24-04-ltsubuntu-25-10ubuntu-26-10ubuntu-26-04-lts
Published: 05/04/2026 (05/04/2026, 07:16:00 UTC)
Source: GCVE Database
Product: mutt

Description

A NULL pointer dereference vulnerability exists in mutt before version 2.3.2 in the show_sig_summary function. This flaw can cause the application to crash, resulting in a denial of service. The vulnerability has a medium severity rating with a CVSS score of 2.5.

CVSS v3.1

Score 2.5low

Attack Vector
Local
Attack Complexity
High
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:L

Affected software

Ubuntu:Pro:16.04:LTSmore threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=esm-infra/xenial
Affected versions
=1.5.23-3.1ubuntu1=1.5.23-3.1ubuntu2=1.5.24-1=1.5.24-1build1=1.5.24-1ubuntu0.1=1.5.24-1ubuntu0.2=1.5.24-1ubuntu0.3=1.5.24-1ubuntu0.4=1.5.24-1ubuntu0.5=1.5.24-1ubuntu0.6=1.5.24-1ubuntu0.6+esm2=1.5.24-1ubuntu0.6+esm3
Ubuntu:Pro:18.04:LTSmore threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=esm-infra/bionic
Affected versions
=1.8.3+neomutt20170609-2build1=1.9.1-2=1.9.1-3=1.9.1-4=1.9.1-5=1.9.2-1=1.9.3-1=1.9.4-2=1.9.4-3=1.9.4-3ubuntu0.1=1.9.4-3ubuntu0.2=1.9.4-3ubuntu0.3=1.9.4-3ubuntu0.4=1.9.4-3ubuntu0.5=1.9.4-3ubuntu0.6=1.9.4-3ubuntu0.6+esm1
Ubuntu:20.04:LTSmore threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=focal
Affected versions
=1.10.1-2.1=1.12.2-1=1.12.2-2=1.13.0-1=1.13.2-1=1.13.2-1ubuntu0.1=1.13.2-1ubuntu0.2=1.13.2-1ubuntu0.3=1.13.2-1ubuntu0.4=1.13.2-1ubuntu0.5=1.13.2-1ubuntu0.6
Ubuntu:22.04:LTSmore threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=jammy
Affected versions
=2.0.5-4.1build1=2.1.3-1=2.1.4-1=2.1.4-1build1=2.1.4-1ubuntu1.1=2.1.4-1ubuntu1.2
Ubuntu:24.04:LTSmore threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=noble
Affected versions
=2.2.9-1=2.2.9-1ubuntu0.23.10.1=2.2.12-0.1=2.2.12-0.1build2=2.2.12-0.1build3=2.2.12-0.1build4
Ubuntu:25.10more threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=questing
Affected versions
=2.2.13-1
Ubuntu:26.10more threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=stonking
Affected versions
=2.2.13-1build2=2.3.2-1=2.4.0-1=2.4.1-1
Ubuntu:26.04:LTSmore threats →ghsa
mutt
pkg:deb/ubuntu/mutt?arch=source&distro=resolute
Affected versions
=2.2.13-1=2.2.13-1build1=2.2.13-1build2

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AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 10/18/2026, 01:36:43 UTC

Technical Analysis

The mutt email client versions before 2.3.2 contain a NULL pointer dereference vulnerability in the show_sig_summary function. This vulnerability can lead to application crashes when triggered, causing denial of service. The CVSS 3.1 base score is 2.5, indicating low impact on confidentiality and integrity but some impact on availability. No known exploits are reported in the wild. The affected versions include multiple specific releases up to and including 2.3.2-1, with no explicit patch information provided.

Potential Impact

The vulnerability causes a denial of service by crashing the mutt application due to a NULL pointer dereference. There is no impact on confidentiality or integrity according to the CVSS vector. No active exploitation is known.

Mitigation Recommendations

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should monitor official mutt or distribution advisories for updates addressing this issue. Until a fix is available, avoid triggering the show_sig_summary functionality if possible.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
UBUNTU-CVE-2026-43864
Osv Schema Version
1.7.0
Ecosystems
["Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:25.10","Ubuntu:26.10","Ubuntu:26.04:LTS"]
Cvss Version
3.1

Threat ID: 6ad3f67b2cdf04f6566668f4

Added to database: 10/17/2026, 22:28:11 UTC

Last enriched: 10/18/2026, 01:36:43 UTC

Last updated: 10/18/2026, 01:36:43 UTC

Views: 4

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