Mattermost versions 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 fails to validate user channel membership when attaching Mattermost posts as comments to Jira issues, which allows an authenticated attacker with access to the Jira plugin to read post content and attachments from channels they do not have access to.
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-fmqf-pmcm-8cx9 Mattermost doesn't validate user channel membership when attaching Mattermost posts as comments to Jira issues
Fixes

Solution

Update Mattermost to versions 11.2.0, 11.1.1, 11.0.6, 10.12.4, 10.11.8 or higher.


Workaround

No workaround given by the vendor.

References
History

Wed, 31 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

Mon, 29 Dec 2025 23:15:00 +0000

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

Wed, 24 Dec 2025 17:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 24 Dec 2025 08:15:00 +0000

Type Values Removed Values Added
Description Mattermost versions 11.1.x <= 11.1.0, 11.0.x <= 11.0.5, 10.12.x <= 10.12.3, 10.11.x <= 10.11.7 fails to validate user channel membership when attaching Mattermost posts as comments to Jira issues, which allows an authenticated attacker with access to the Jira plugin to read post content and attachments from channels they do not have access to.
Title Unauthorized Read Access to Private Channel Posts via Mattermost Jira Plugin
Weaknesses CWE-863
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2025-12-24T16:36:22.999Z

Reserved: 2025-11-27T18:02:05.323Z

Link: CVE-2025-13767

cve-icon Vulnrichment

Updated: 2025-12-24T16:36:17.251Z

cve-icon NVD

Status : Analyzed

Published: 2025-12-24T08:15:45.553

Modified: 2025-12-31T18:56:27.667

Link: CVE-2025-13767

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-12-29T22:34:40Z

Weaknesses