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.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-jf5h-xfw4-p8gp Mattermost GitHub Plugin Bot Identity Validation Bypass Allows Arbitrary GitHub Reaction Injection
Fixes

Solution

Update Mattermost to versions 11.1.0, 10.11.7 or higher. Alternatively, update the Mattermost GitHub plugin to version 2.5.0 or higher.


Workaround

No workaround given by the vendor.

References
History

Mon, 29 Dec 2025 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost mattermost Server
CPEs cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Vendors & Products Mattermost mattermost Server

Wed, 17 Dec 2025 21:30:00 +0000

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost

Wed, 17 Dec 2025 12:30:00 +0000

Type Values Removed Values Added
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.
Title Mattermost GitHub Plugin allows unauthorized GitHub reactions via reaction forwarding hijacking
Weaknesses CWE-1287
References
Metrics cvssV3_1

{'score': 3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:L/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2025-12-17T16:48:08.118Z

Reserved: 2025-11-18T10:07:28.143Z

Link: CVE-2025-13352

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-12-17T13:15:56.627

Modified: 2025-12-29T18:50:47.780

Link: CVE-2025-13352

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-12-17T21:18:45Z

Weaknesses