CVE-2025-53971 | Channel and Team Membership APIs inadvertently allow loss of Member privileges.

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.

Published: 2025-08-21 Last update: 2025-08-25 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-53971 is rated Low Risk (21.4/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-53971

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-07 0.02% 0.06% +0.03%
2 2025-08-21 — 0.02% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-53971

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.8 3.1 LOW
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H)
They need powerful rights—admin, root, or similar—before this pays off.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 1.2 2.5 [email protected]

Weakness enumeration for CVE-2025-53971

GitHub Security Advisory for CVE-2025-53971

GHSA-4276-cm8c-788h · Severity: low · Ecosystem: go — Mattermost Fails to Properly Validate Team Role Modification

Affected software / configurations for CVE-2025-53971

Vendor Product Version Raw CPE
mattermost mattermost_server >= 9.11.0, < 9.11.18 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
mattermost mattermost_server >= 10.5.0, < 10.5.9 cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*

References for CVE-2025-53971

URL Tags
https://mattermost.com/security-updates Vendor Advisory
cvelogic Threat Intelligence