CVE-2026-8075: Mattermost Desktop

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Mattermost Desktop App versions <=6.2 5.5.13 6.0.2.0 fail to properly null check when checking for headers in the Mattermost Desktop App which allows any user to crash another channel members Desktop App via posting a malicious link with an embedded image that misses one of those headers. Mattermost Advisory ID: MMSA-2026-00668

Affected products

• Mattermost Mattermost Desktop: from 5.5.13, before 5.13.6 (fixed in 5.13.6); from 6.0.2, before 6.2.1 (fixed in 6.2.1); after 6.2.1, before 6.3 (fixed in 6.3)

Published 2026-07-17. Last modified 2026-07-30.