Mattermost 9.11.x Private Channel Admin Grant via Permalink
CVE-2025-27715 Published on March 21, 2025
Auto-Enrollment of Team Admins into Private Channels without explicit consent
Mattermost versions 9.11.x <= 9.11.8 fail to prompt for explicit approval before adding a team admin to a private channel, which team admins to joining private channels via crafted permalink links without explicit consent from them.
Vulnerability Analysis
CVE-2025-27715 can be exploited with network access, and requires 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 and integrity, and no impact on 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-2025-27715 has been classified to as an AuthZ vulnerability or weakness.
Products Associated with CVE-2025-27715
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Affected Versions
Mattermost:- Version 9.11.0, <= 9.11.8 is affected.
- Version 10.5.0 is unaffected.
- Version 9.11.9 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.