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mutt before 2.3.2 sometimes truncates the hash_passwd by one byte for IMAP auth_cram MD5 digest. (CVE-2026-43860)

0
Medium
VulnerabilityCVE-2026-43860gcveosvubuntu-cve-2026-43860cve-2026-43860ubuntu-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 vulnerability in mutt before version 2.3.2 causes the hash_passwd to sometimes be truncated by one byte during IMAP auth_cram MD5 digest processing. This issue can lead to integrity problems in authentication. The CVSS score is 3.7, indicating a medium severity level.

CVSS v3.1

Score 3.7low

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

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

Run on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.

AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 10/18/2026, 01:37:13 UTC

Technical Analysis

The mutt email client versions prior to 2.3.2 have a flaw where the hash_passwd value used in the IMAP auth_cram MD5 digest authentication mechanism is occasionally truncated by one byte. This truncation can affect the integrity of the authentication process, potentially causing incorrect authentication behavior. The vulnerability is identified as CVE-2026-43860 and has a CVSS 3.1 base score of 3.7, with network attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, no confidentiality impact, limited integrity impact, and no availability impact.

Potential Impact

The vulnerability impacts the integrity of the IMAP authentication process by truncating the hash_passwd by one byte, which could lead to authentication failures or unexpected authentication behavior. There is no confidentiality or availability impact reported. The medium severity reflects the limited impact on integrity and the complexity of exploitation.

Mitigation Recommendations

No explicit patch or remediation details are provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should verify if updates to mutt version 2.3.2 or later are available and apply them once confirmed.

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Technical Details

Gcve Source
db.gcve.eu
Osv Id
UBUNTU-CVE-2026-43860
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: 6ad3f67b2cdf04f6566668f8

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

Last enriched: 10/18/2026, 01:37:13 UTC

Last updated: 10/18/2026, 01:37:13 UTC

Views: 5

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