Mattermost Server 10.11.x < 10.11.22 / 11.7.x < 11.7.7 Multiple Vulnerabilities (MMSA-2026-00672, MMSA-2026-00675, MMSA-2026-00704)

The version of Mattermost Server installed on the remote host is affected by multiple vulnerabilities as referenced in the MMSA-2026-00672, MMSA-2026-00675, MMSA-2026-00704 advisories. - Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to prevent guest users from receiving Board Admin...

Vulnerabilities in Mattermost

Mattermost, Inc. has identified vulnerabilities in Mattermost versions 10.11.x, 11.7.x, and 11.8.x, including the GitLab plugin up to version 11.8. These vulnerabilities relate to various aspects of the Mattermost software, such as incorrect validation of WebSocket command fields, incorrect...

CVE-2026-16044

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID:...

EUVD-2026-60211

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID:...

CVE-2026-16044

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID:...

PT-2026-76669

Mattermost versions 11.7.x = 11.7.6, 10.11.x = 10.11.21 fail to prevent guest users from receiving Board Admin privileges during board archive import which allows a board member to escalate a guest user to Board Admin via importing a crafted .boardarchive file. Mattermost Advisory ID:...

CVE-2026-41419

4ga Boards is a boards system for realtime project management. Prior to 3.3.5, a path traversal vulnerability allows an authenticated user with board import privileges to make the server ingest arbitrary host files as board attachments during BOARDS archive import. Once imported, the file can be...