What is CVE-2026-4643?

CVE-2026-4643 is a low-severity vulnerability in Mattermost, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 3.5/10. Published 2026-05-18.

How severe is CVE-2026-4643?

Low severity. CVSS v3 base score is 3.5 out of 10.

Vulnerability in Mattermost

CVE-2026-4643

Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent server-rendered content from closing an underlying application view in the Mattermost Desktop App which allows a malicious server or plugin to crash the desktop client vi…

EPSS: 0.000 (10.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 3.5 (Low). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L.

Affected products

Mattermost — versions 0, 6.2.0, 6.1.1.0
Mattermost Mattermost_desktop

Weakness classification (CWE)

CWE-754 — Improper Check for Unusual or Exceptional Conditions

References

responsibledisclosure@mattermost.com (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-4643?: CVE-2026-4643 is a low-severity vulnerability in Mattermost, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 3.5/10. Published 2026-05-18.
How severe is CVE-2026-4643?: Low severity. CVSS v3 base score is 3.5 out of 10.