Vulnerability in Mattermost
CVE-2025-9078
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.10.x <= 10.10.1, 10.9.x <= 10.9.3 fail to properly validate cache keys for link metadata which allows authenticated users to access unauthorized posts and poison link previews via hash collision attacks on FNV-1 hashing
EPSS: 0.001 (3.8th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.
Affected products
- Mattermost — versions 10.8.0, 10.5.0, 9.11.0
- Mattermost Mattermost_server
Weakness classification (CWE)
Public proof-of-concept exploits
References
- responsibledisclosure@mattermost.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-9078?
- CVE-2025-9078 is a medium-severity vulnerability in Mattermost, classified under Use of Weak Hash. CVSS score: 4.3/10. Published 2025-09-15.
- How severe is CVE-2025-9078?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2025-9078 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.