How severe is CVE-2025-53971?

CVE-2025-53971 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2025-53971 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-53971?

CVE-2025-53971 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-53971?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-53971 have an EU (EUVD) identifier?

Yes. CVE-2025-53971 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25413.

When was CVE-2025-53971 published?

CVE-2025-53971 was published on 2025-08-21 and last updated on 2026-06-17.

CVE-2025-53971

CVE-2025-53971 is a low-severity vulnerability in Mattermost Mattermost Server with a CVSS 3.x base score of 3.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Low (CVSS 3.x base score 3.8)
EPSS exploit prediction: 0% (9th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-25413
Weakness: CWE-863
Affected product: Mattermost Mattermost Server
Published: 2025-08-21
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-53971?: 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.
How severe is CVE-2025-53971?: CVE-2025-53971 has a CVSS 3.x base score of 3.8, rated low severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-53971 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (9th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-53971?: CVE-2025-53971 affects Mattermost Mattermost Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-53971?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-53971 have an EU (EUVD) identifier?: Yes. CVE-2025-53971 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-25413.
When was CVE-2025-53971 published?: CVE-2025-53971 was published on 2025-08-21 and last updated on 2026-06-17.

References

https://mattermost.com/security-updates

Affected products (1)

cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

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