CVE-2024-29221: Invite ID available to team admins even without the "Add Members" permission

Severity: low (CVSS 3.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-04-05 · updated 2026-06-17
Weakness: CWE-284

Description

Improper Access Control in Mattermost Server versions 9.5.x before 9.5.2, 9.4.x before 9.4.4, 9.3.x before 9.3.3, 8.1.x before 8.1.11 lacked proper access control in the `/api/v4/users/me/teams` endpoint allowing a team admin to get the invite ID of their team, thus allowing them to invite users, even if the "Add Members" permission was explicitly removed from team admins.

Affected products

Mattermost: from 8.1.0 before 8.1.11; from 9.3.0 before 9.3.3; from 9.4.0 before 9.4.4; from 9.5.0 before 9.5.2 — fixed in 8.1.11, 9.3.3, 9.4.4, 9.5.2

How to fix

Upgrade to a fixed version: Mattermost 8.1.11, 9.3.3, 9.4.4, 9.5.2. Check the vendor advisory for mitigations.

References

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