CVE-2025-10545: Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users…

PriorityP423medium4.3CVSS 3.1

AVNACLPRLUINSUCLINAN

EPSS

0.30%

22.4th percentile

Mattermost versions 10.5.x <= 10.5.10, 10.11.x <= 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the `/api/v4/channels/{channel_id}/members` endpoint

Affected

9 ranges

Vendor	Product	Version range	Fixed in
github.com	mattermost_mattermost-server	>= 10.11.0 < 10.11.3	10.11.3
github.com	mattermost_mattermost-server	>= 10.11.0+incompatible < 10.11.3+incompatible	10.11.3+incompatible
github.com	mattermost_mattermost-server	>= 10.5.0 < 10.5.11	10.5.11
github.com	mattermost_mattermost-server	>= 10.5.0+incompatible < 10.5.11+incompatible	10.5.11+incompatible
github.com	mattermost_mattermost_server_v8	>= 0 < 8.0.0-20250820115038-ff30b84049f0	8.0.0-20250820115038-ff30b84049f0
mattermost	mattermost	10.11.0 – 10.11.2	—
mattermost	mattermost	10.5.0 – 10.5.10	—
mattermost	mattermost_server	>= 10.11.0 < 10.11.3	10.11.3
mattermost	mattermost_server	>= 10.5.0 < 10.5.11	10.5.11

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