CVE-2026-10542

Playbooks channel action update validation issue

Published Sep 14, 2026 CVSS 3.1 · 5 Medium EPSS < 1% KEV · Not listed
Description
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel managers to update actions in other channels via the channel action update endpoint.. Mattermost Advisory ID: MMSA-2026-00692

Remediation

Vendor Solution

Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.8, 10.11.23 or higher.

Tracking

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Advisories

No advisories available
References
History
Type Values Removed Values Added
First Time appeared Mattermost mattermost Server
CPEs cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
Vendors & Products Mattermost mattermost Server
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
First Time appeared Mattermost
Mattermost mattermost
Vendors & Products Mattermost
Mattermost mattermost
Type Values Removed Values Added
Description Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to validate channel action ownership which allows channel managers to update actions in other channels via the channel action update endpoint.. Mattermost Advisory ID: MMSA-2026-00692
Title Playbooks channel action update validation issue
Weaknesses CWE-639
References
Metrics cvssV3_1

{'score': 5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Mattermost
Published
Updated
Sep 14, 2026, 11:19 AM
Reserved
Jun 1, 2026, 12:34 PM
Status
Analyzed
Published
Sep 14, 2026, 11:17 AM
Modified
Oct 7, 2026, 4:32 PM