CVE-2025-13352

Mattermost GitHub Plugin allows unauthorized GitHub reactions via reaction forwarding hijacking

State: Published
Severity: 3.0 Low
Published: Dec 17, 2025
Updated: Dec 17, 2025
Reserved: Nov 18, 2025

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.

Scores

CVSS	Score	Vector	Source
3.1	3.0 Low	CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N	Mattermost

Weaknesses

CWE-1287 Improper Validation of Specified Type of Input

Affected Products

Product	Versions
MattermostMattermost	10.11.0 through 10.11.6Affected 11.1.0Not affected 10.11.7Not affected

References

https://mattermost.com/security-updates

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