DoS attack via login attempts with multi-megabyte passwords
Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly handle very long passwords, which allows an attacker to overload the server CPU and memory via executing login attempts with multi-megabyte passwords. Mattermost Advisory ID: MMSA-2026-00587
Severity high: primary CNA CVSS 7.5 v3.1 (worst CNA-provided scenario) Not listed in this KEV snapshot. Forecast present in this snapshot.
Published 2026-03-16T12:02:23.223Z. Updated 2026-03-16T13:49:55.523Z.