CVE-2025-53971

low-risk
Published 2025-08-21

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.

Do I need to act?

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0.04% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
3
CVSS 3.8/10 Low
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

References (1)

22
/ 100
low-risk
Severity 17/34 · Moderate
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal