CVE-2018-21250: Mattermost Server

Medium severity, CVSS 6.5. EPSS: 1.1% chance of exploitation in the next 30 days.

An issue was discovered in Mattermost Server before 5.2.2, 5.1.2, and 4.10.4. It allows remote attackers to cause a denial of service (memory consumption) via crafted image dimensions.

Affected products

• Mattermost Mattermost Server: before 4.10.4 (fixed in 4.10.4); from 5.1.0, before 5.1.2 (fixed in 5.1.2); from 5.2.0, before 5.2.2 (fixed in 5.2.2)

Published 2020-06-19. Last modified 2026-06-17.