Arbitrary file upload in Mattermost
CVE-2025-49222
Mattermost versions 10.8.x <= 10.8.3, 10.5.x <= 10.5.8, 9.11.x <= 9.11.17, 10.9.x <= 10.9.2, 10.10.x <= 10.10.0 fail to validate upload types in remote cluster upload sessions which allows a system admin to upload non-attachment file types via shared channels that could potentially be placed in arbitrary filesystem directories.
Vulnerability class: Unrestricted File Upload
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (20.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Mattermost — versions 10.8.0, 10.5.0, 9.11.0
- Mattermost Server — versions 10.10.0
Weakness classification (CWE)
References
- mattermost.com/security-updates (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-49222?
- CVE-2025-49222 is a medium-severity vulnerability in Mattermost, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 6.8/10. Published 2025-08-21.
- How severe is CVE-2025-49222?
- Medium severity. CVSS v3 base score is 6.8 out of 10.