Auth bypass in Mattermost
CVE-2025-9081
Mattermost versions 10.5.x <= 10.5.8, 9.11.x <= 9.11.17 fail to properly validate access controls which allows any authenticated user to download sensitive files via board file download endpoint using UUID enumeration
Vulnerability class: IDOR (Insecure Direct Object Reference)
EPSS: 0.003 (16.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.1 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Mattermost — versions 10.5.0, 9.11.0, 10.11.0
- Mattermost Mattermost_server
Weakness classification (CWE)
Public proof-of-concept exploits
References
- responsibledisclosure@mattermost.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-9081?
- CVE-2025-9081 is a low-severity vulnerability in Mattermost, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 3.1/10. Published 2025-09-19.
- How severe is CVE-2025-9081?
- Low severity. CVSS v3 base score is 3.1 out of 10.
- Is CVE-2025-9081 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.