CVE-2023-5196: Mattermost

Medium severity, CVSS 6.5. EPSS: 0.7% chance of exploitation in the next 30 days.

Mattermost fails to enforce character limits in all possible notification props allowing an attacker to send a really long value for a notification_prop resulting in the server consuming an abnormal quantity of computing resources and possibly becoming temporarily unavailable for its users.

Affected products

• Mattermost Mattermost: from 7.0.0, before 7.8.10 (fixed in 7.8.10); from 8.0.0, before 8.0.2 (fixed in 8.0.2); from 8.1.0, before 8.1.1 (fixed in 8.1.1)

Published 2023-09-29. Last modified 2026-06-17.