What is CVE-2026-3471?

CVE-2026-3471 is a medium-severity vulnerability in Mattermost, classified under CWE-939. CVSS score: 6.5/10. Published 2026-05-18.

How severe is CVE-2026-3471?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Mattermost

CVE-2026-3471

Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent an invalid URL from loading in a pop-up window in the Mattermost Desktop App which allows a malicious server owner to repeated crash the application via calling {{window…

EPSS: 0.000 (11.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

Affected products

Mattermost — versions 0, 6.2.0, 6.1.1.0
Mattermost Mattermost_desktop

Weakness classification (CWE)

CWE-939

References

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

Frequently asked questions

What is CVE-2026-3471?: CVE-2026-3471 is a medium-severity vulnerability in Mattermost, classified under CWE-939. CVSS score: 6.5/10. Published 2026-05-18.
How severe is CVE-2026-3471?: Medium severity. CVSS v3 base score is 6.5 out of 10.