Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603
References
History

Wed, 15 Apr 2026 13:45:00 +0000

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

Wed, 15 Apr 2026 13:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Wed, 15 Apr 2026 10:45:00 +0000

Type Values Removed Values Added
Description Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603
Title Connected Workspaces: Malicious remote server can manipulate arbitrary user's status
Weaknesses CWE-862
References
Metrics cvssV3_1

{'score': 2.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: Mattermost

Published:

Updated: 2026-04-15T13:08:35.452Z

Reserved: 2026-03-16T08:51:03.250Z

Link: CVE-2026-27769

cve-icon Vulnrichment

Updated: 2026-04-15T13:08:32.237Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-04-15T13:44:47Z