Vulnerability in Mattermost
CVE-2025-27936
Mattermost Plugin MSTeams versions <2.1.0 and Mattermost Server versions 10.5.x <=10.5.1 with the MS Teams plugin enabled fail to perform constant time comparison on a MSTeams plugin webhook secret which allows an attacker to retrieve the webhook secret of the MSTeams plugin via a timing attack during webhook secret comparison.
EPSS: 0.003 (24.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
Affected products
- Mattermost — versions 10.5.0, 10.6.0, 10.5.2
- Mattermost Mattermost_server
- Mattermost Ms_teams
Weakness classification (CWE)
Public proof-of-concept exploits
References
- responsibledisclosure@mattermost.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-27936?
- CVE-2025-27936 is a medium-severity vulnerability in Mattermost, classified under CWE-208. CVSS score: 5.3/10. Published 2025-04-16.
- How severe is CVE-2025-27936?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2025-27936 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.