mutt before 2.3.2 does not check for '\0' in url_pct_decode. (CVE-2026-43861)
Description
A vulnerability exists in mutt versions before 2.3.2 where the function url_pct_decode does not properly check for null ('\0') characters. This issue has a CVSS 3.7 score and is rated medium severity. It may lead to limited impact on integrity but does not affect confidentiality or availability. Multiple specific mutt package versions are affected. No known exploits are reported in the wild. No patch or remediation details are provided in the source data.
CVSS v3.1
Score 3.7low
Affected software
pkg:deb/ubuntu/mutt?arch=source&distro=esm-infra/xenialpkg:deb/ubuntu/mutt?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/mutt?arch=source&distro=focalpkg:deb/ubuntu/mutt?arch=source&distro=jammypkg:deb/ubuntu/mutt?arch=source&distro=noblepkg:deb/ubuntu/mutt?arch=source&distro=questingpkg:deb/ubuntu/mutt?arch=source&distro=stonkingpkg:deb/ubuntu/mutt?arch=source&distro=resoluteRun 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
Technical Analysis
The mutt email client before version 2.3.2 contains a vulnerability in the url_pct_decode function due to lack of validation for null ('\0') characters. This flaw could potentially allow an attacker to influence the integrity of the application, though the exact impact is limited as per the CVSS vector (AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N). The vulnerability affects numerous specific mutt package versions listed, including various Ubuntu builds. There is no indication of active exploitation or available patches in the provided data.
Potential Impact
The vulnerability impacts the integrity of the mutt application but does not compromise confidentiality or availability. The attack vector is network with high attack complexity and no privileges or user interaction required. The overall severity is medium. There are no known exploits in the wild according to the provided information.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no official fix or patch links are provided, users should monitor vendor communications for updates and consider upgrading to mutt version 2.3.2 or later once confirmed safe.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-43861
- 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: 6ad3f67b2cdf04f6566668f7
Added to database: 10/17/2026, 22:28:11 UTC
Last enriched: 10/18/2026, 01:37:07 UTC
Last updated: 10/18/2026, 01:37:07 UTC
Views: 4
Community Reviews
0 reviewsCrowdsource mitigation strategies, share intel context, and vote on the most helpful responses. Sign in to add your voice and help keep defenders ahead.
Want to contribute mitigation steps or threat intel context? Sign in or create an account to join the community discussion.
Actions
Updates to AI analysis require Pro Console access. Upgrade inside Console → Billing.
Need more coverage?
Upgrade to Pro Console for AI refresh and higher limits.
For incident response and remediation, OffSeq services can help resolve threats faster.
Latest Threats
Check if your credentials are on the dark web
Instant breach scanning across billions of leaked records. Free tier available.