Low severity · published Dec 17, 2025
CVE-2025-13352
Mattermost GitHub Plugin allows unauthorized GitHub reactions via reaction forwarding hijacking
3.0
CVSS
0.2%
EPSS
No
On KEV
Description
Mattermost versions 10.11.x <= 10.11.6 and Mattermost GitHub plugin versions <=2.4.0 fail to validate plugin bot identity in reaction forwarding which allows attackers to hijack the GitHub reaction feature to make users add reactions to arbitrary GitHub objects via crafted notification posts.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
MA
Mattermost · Mattermost
10.11.0 through 10.11.6 · source: vendor
MS
Mattermost Server · Mattermost
10.11.0 before 10.11.7 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-13352
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-13352
Vendor Advisory
https://mattermost.com/security-updates
More from Mattermost
9.9
CVE-2026-4858
Path traversal in integration action URL leading to arbitrary API execution via system admin’s auth token.
9.9
CVE-2025-12421
Account Takeover via Code Exchange Endpoint
9.9
CVE-2025-12419
Account takeover on OAuth/OpenID-enabled servers
9.6
CVE-2024-39777
Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6, 9.7.x <= 9.7.5 and 9.8.x <= 9.8.1 fail to disallow unsolicited invites to expose access to local channels, when shared channels…
9.3
CVE-2026-12985
Mattermost DCR redirect URI allowlist bypass via improper URL component validation