What is the CVSS score of CVE-2026-1046?

CVE-2026-1046 has a CVSS 3.1 base score of 7.6 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L. EPSS exploitation probability: 0.0%.

Which versions of Mattermost Desktop are affected by CVE-2026-1046?

Mattermost Desktop App users running versions 6.0, 6.2.0, or 5.2.13.0 are at risk of arbitrary code execution if they click malicious help menu links served by a compromised or malicious Mattermost…

How to fix or mitigate CVE-2026-1046?

Within 24 hours: inventory all Mattermost Desktop App deployments and identify affected versions (≤6.0, 6.2.0, 5.2.13.0); communicate risk to users and restrict access if possible. Within 7 days: disable the Help menu feature via server configuration, or implement network controls to restrict users from connecting to untrusted Mattermost servers. Within 30 days: monitor vendor for patch availability and test in pre-production environment; upgrade all affected instances to patched versions upon release; conduct audit of Mattermost server configurations to detect any suspicious help link modifications.

Mattermost Desktop CVE-2026-1046

HIGH

Improper Authorization in Handler for Custom URL Scheme (CWE-939)

2026-02-16 responsibledisclosure@mattermost.com

Information Disclosure Mattermost Desktop

7.6

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.6 HIGH

AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

None

Availability

Low

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

CVE Published

Feb 16, 2026 - 13:16 nvd

HIGH 7.6

DescriptionCVE.org

Mattermost Desktop App versions <=6.0 6.2.0 5.2.13.0 fail to validate help links which allows a malicious Mattermost server to execute arbitrary executables on a user’s system via the user clicking on certain items in the Help menu Mattermost Advisory ID: MMSA-2026-00577

AnalysisAI

Arbitrary code execution in Mattermost Desktop App through version 6.2.0 results from insufficient validation of help menu links, enabling a malicious server administrator to execute arbitrary executables on affected users' systems when they click specially crafted help items. This vulnerability affects multiple versions including 5.2.13.0 and 6.0, requiring user interaction and authenticated server access to exploit. No patch is currently available for this HIGH severity vulnerability.