CVE-2026-3637

published 2026-05-18

CVE-2026-3637: Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which…

medium 4.3 CVSS 3.1

AV N AC L PR L UI N S U C N I L A N

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to check the create_post channel permission during post edit operations which allows an authenticated attacker with revoked posting privileges to modify their existing posts via direct API requests to the post update and patch endpoints.. Mattermost Advisory ID: MMSA-2026-00627

Affected

11 ranges

Vendor	Product	Version range	Fixed in
github.com	mattermost_mattermost-server	>= 0 < 5.3.2-0.20260316171743-090408f09f53	5.3.2-0.20260316171743-090408f09f53
github.com	mattermost_mattermost_server_v8	>= 0 < 8.0.0-20260316171743-090408f09f53	8.0.0-20260316171743-090408f09f53
github.com	mattermost_mattermost_server_v8	>= 10.11.0 < 10.11.14	10.11.14
github.com	mattermost_mattermost_server_v8	>= 11.4.0 < 11.4.4	11.4.4
github.com	mattermost_mattermost_server_v8	>= 11.5.0 < 11.5.2	11.5.2
mattermost	mattermost	10.11.0 – 10.11.13	—
mattermost	mattermost	11.4.0 – 11.4.3	—
mattermost	mattermost	11.5.0 – 11.5.1	—
mattermost	mattermost_server	>= 10.11.0 < 10.11.14	10.11.14
mattermost	mattermost_server	>= 11.4.0 < 11.4.4	11.4.4
mattermost	mattermost_server	>= 11.5.0 < 11.5.2	11.5.2

CWE-862