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.
References (1)
Scores
CVSS v3
3.0
EPSS
0.0008
EPSS Percentile
24.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-1287
Status
published
Products (4)
mattermost/mattermost
0 - 10.11.7-0.20251106103514-3b05384dd014Go
mattermost/mattermost
10.11.0-rc1 - 10.11.7-0.20251106103514-3b05384dd014Go
mattermost/mattermost-plugin-github
0 - 1.0.1-0.20250829075715-0deffcfc6beeGo
mattermost/mattermost_server
10.11.0 - 10.11.7
Published
Dec 17, 2025
Tracked Since
Feb 18, 2026