CVE-2026-24661: Mattermost

Medium severity, CVSS 6.5. EPSS: 0.3% chance of exploitation in the next 30 days.

Mattermost Plugins versions <=2.1.3.0 fail to limit the request body size on the {{/changes}} webhook endpoint which allows an authenticated attacker to cause memory exhaustion and denial of service via sending an oversized JSON payload. Mattermost Advisory ID: MMSA-2026-00611

Affected products

• Mattermost Mattermost: before 2.3.2.0 (fixed in 2.3.2.0)

Published 2026-04-09. Last modified 2026-06-17.