VDB-360945 · CVE-2026-43861 · Nessus 321070

mutt up to 2.3.1 url_pct_decode neutralization of null byte

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.3	$0-$5k	0.00

Summaryinfo

A vulnerability marked as problematic has been reported in mutt up to 2.3.1. This affects the function url_pct_decode. Performing a manipulation results in neutralization of null byte. This vulnerability is known as CVE-2026-43861. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in mutt up to 2.3.1. This affects the function url_pct_decode. The manipulation with an unknown input leads to a neutralization of null byte vulnerability. CWE is classifying the issue as CWE-158. The product receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-43861 since 05/04/2026. The exploitability is told to be difficult. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 321070 (SUSE SLES12 Security Update : mutt (SUSE-SU-2026:2300-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.3.2 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (321070) and CERT Bund (WID-SEC-2026-1343). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

Open Source mutt

Productinfo

Type

Mail Client Software

Name

mutt

Version

License

open-source

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 5.0
VulDB Temp Score: 4.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 3.7
CNA Vector (MITRE): 🔒

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Neutralization of null byte
CWE: CWE-158 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 321070
Nessus Name: SUSE SLES12 Security Update : mutt (SUSE-SU-2026:2300-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: mutt 2.3.2

Timelineinfo

05/04/2026 Advisory disclosed
05/04/2026 +0 days CVE reserved
05/04/2026 +0 days VulDB entry created
06/14/2026 +41 days VulDB entry last update

Sourcesinfo

Advisory: 12f54fe3b61f761c096fe95e95d5e3072af00ed2
Status: Confirmed

CVE: CVE-2026-43861 (🔒)
GCVE (CVE): GCVE-0-2026-43861
GCVE (VulDB): GCVE-100-360945
CERT Bund: WID-SEC-2026-1343 - mutt: Mehrere Schwachstellen

Entryinfo

Created: 05/04/2026 09:21
Updated: 06/14/2026 21:39
Changes: 05/04/2026 09:21 (64), 05/04/2026 12:54 (7), 06/14/2026 21:39 (2)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.