CVE-2026-8683

EUVD-2026-36732
Mattermost Desktop App versions <=6.1 5.5.13.0 fail to account for attempting to open extremely long URLs in the Mattermost Desktop App which allows a malicious server owner to crash the application via including a script to call window.open on a very large URL. Mattermost Advisory ID: MMSA-2026-00652
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%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_desktop
𝑥
≤ 5.13.0
mattermostmattermost_desktop
6.1.0 ≤
𝑥
≤ 6.1.5
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 5.5.13
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates