What is CVE-2026-1046?

CVE-2026-1046 is a high-severity vulnerability in Mattermost, classified under CWE-939. CVSS score: 7.6/10. Published 2026-02-16.

How severe is CVE-2026-1046?

High severity. CVSS v3 base score is 7.6 out of 10.

Vulnerability in Mattermost

CVE-2026-1046

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

Published 2026-02-16 · last modified 2026-10-15.

CVSS v3 metric

CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:L.

EPSS exploit prediction

EPSS: 0.003 (16.5th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 16th percentile — 16.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.000

Affected products

Mattermost — versions 0, 6.1.0, 6.0.3.0
Mattermost Desktop

Weakness classification (CWE)

CWE-939

References

mattermost.com/security-updates (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-1046?: CVE-2026-1046 is a high-severity vulnerability in Mattermost, classified under CWE-939. CVSS score: 7.6/10. Published 2026-02-16.
How severe is CVE-2026-1046?: High severity. CVSS v3 base score is 7.6 out of 10.