Vulnerability · Published Aug 21, 2025 · Assigned by Mattermost
CVE-2025-53971Channel and Team Membership APIs inadvertently allow loss of Member privileges.
Low 3.8
In plain English
A low-severity incorrect authorization in Mattermost from Mattermost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)3.8Low
Exploit odds (30 days)0.2%top 89.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Mattermost versions 10.5.x <= 10.5.8, 9.11.x <= 9.11.17 fail to properly validate authorization for team scheme role modifications which allows Team Admins to demote Team Members to Guests via the PUT /api/v4/teams/team-id/members/user-id/schemeRoles API endpoint.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | 10.5.9+incompatible, 9.11.18+incompatible | GO-2025-3902 |
| Go | github.com/mattermost/mattermost-server | 9.11.18 | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server | 10.5.9 | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server/v5 | no fix listed | GO-2025-3902 |
| Go | github.com/mattermost/mattermost-server/v5 | no fix listed | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server/v6 | no fix listed | GHSA-4276-cm8c-788h |
| Go | github.com/mattermost/mattermost-server/v6 | no fix listed | GO-2025-3902 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20250721095846-c602a4a78e1f | GO-2025-3902 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20250721095846-c602a4a78e1f | GHSA-4276-cm8c-788h |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 10.5.0 – through 10.5.89.11.0 – through 9.11.17 |
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N