NetSight
low3.1

CVE-2025-11777

Mattermost Incorrect Authorization vulnerability

Impact

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API, which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint.

Affected packages

EcosystemPackageAffectedFixed in
gogithub.com/mattermost/mattermost-server>= 10.11.0, < 10.11.410.11.4
gogithub.com/mattermost/mattermost/server/v8< 8.0.0-20250905150616-ba86dfc5876b8.0.0-20250905150616-ba86dfc5876b
gogithub.com/mattermost/mattermost< 5.3.2-0.20250905150616-ba86dfc5876b5.3.2-0.20250905150616-ba86dfc5876b
gogithub.com/mattermost/mattermost-server/v5< 5.3.2-0.20250905150616-ba86dfc5876b5.3.2-0.20250905150616-ba86dfc5876b
gogithub.com/mattermost/mattermost-server/v6< 5.3.2-0.20250905150616-ba86dfc5876b5.3.2-0.20250905150616-ba86dfc5876b

Affected products

VendorProductAffected versions
MattermostMattermost Server
from 10.5.0 before 10.5.12
from 10.11.0 before 10.11.4

Weakness classification

References