Mattermost <=10.5.4 API /api/v4/teams Access Bypass Guest View Public Teams
CVE-2025-4128 Published on June 11, 2025
Mattermost Guest User Information Disclosure Vulnerability
Mattermost versions 10.5.x <= 10.5.4, 9.11.x <= 9.11.13 fail to properly restrict API access to team information, allowing guest users to bypass permissions and view information about public teams they are not members of via a direct API call to /api/v4/teams/{team_id}.
Vulnerability Analysis
CVE-2025-4128 is exploitable with network access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have a small impact on confidentiality, a small impact on integrity and availability.
Weakness Type
What is an AuthZ Vulnerability?
The software performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. This allows attackers to bypass intended access restrictions.
CVE-2025-4128 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2025-4128
stack.watch emails you whenever new vulnerabilities are published in Mattermost Server or MatterMost. Just hit a watch button to start following.
Affected Versions
Mattermost:- Version 10.5.0, <= 10.5.4 is affected.
- Version 9.11.0, <= 9.11.13 is affected.
- Version 10.8.0 is unaffected.
- Version 10.5.5 is unaffected.
- Version 9.11.14 is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.