CVE-2026-3471

EUVD-2026-30757
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.open('javascript:alert()');}}. Mattermost Advisory ID: MMSA-2026-00618
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
6.5 MEDIUM
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Base Score
CVSS 3.x
EPSS Score
Percentile: 10%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 6.0.1
CNA
mattermostmattermost
𝑥
≤ 5.4.13
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates