What’s Vulnerable › Vulnerabilities
CVE-2025-27715: Auto-Enrollment of Team Admins into Private Channels without explicit consent
- Severity: low (CVSS 2.7 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-03-21 · updated 2026-06-17
- Weakness: CWE-863
Description
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.
Affected products
- Mattermost: from 9.11.0 before 9.11.9 — fixed in 9.11.9
How to fix
Upgrade to a fixed version: Mattermost 9.11.9. Check the vendor advisory for mitigations.
References
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