CVE-2026-0997 Mattermost Zoom Plugin channel preference API lacks authorization checks

What is CVE-2026-0997?

CVE-2026-0997 is a medium-severity missing authorization vulnerability in Mattermost Mattermost Server, published on 16 Feb 2026. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Mattermost versions 11.1.x <= 11.1.2, 10.11.x <= 10.11.9, 11.2.x <= 11.2.1 and Mattermost Plugin Zoom versions <=1.11.0 fail to validate the authenticated user when processing {{/plugins/zoom/api/v1/channel-preference}}, which allows any logged-in user to change Zoom meeting restrictions for arbitrary channels via crafted API requests.. Mattermost Advisory ID: MMSA-2025-00558

Weakness: CWE-863

Which versions are affected by CVE-2026-0997?

3 open source packages ship an affected version, including github.com/mattermost/mattermost-plugin-zoom. It affects 2 products.

Products include Mattermost Mattermost Server, Mattermost Zoom.

How do I fix CVE-2026-0997?

Upgrade github.com/mattermost/mattermost-plugin-zoom to 1.11.0 or later.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-0997 being exploited?

There is no known exploitation of CVE-2026-0997 in the wild and no public exploit code.

Other vulnerabilities in Mattermost Mattermost Server

• CVE-2025-12419 Account takeover on OAuth/OpenID-enabled servers Critical 9.9
• CVE-2025-12421 Account Takeover via Code Exchange Endpoint Critical 9.9
• CVE-2025-4981 Path Traversal Leading to RCE by Any Authenticated Mattermost User Critical 9.9
• CVE-2025-20051 Arbitrary file read via block duplication in Mattermost Boards Critical 9.9
• CVE-2025-25279 Arbitrary file read in Mattermost Boards via import & export board archive Critical 9.9

All Mattermost Mattermost Server vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-2phx-frhf-xr55, GO-2026-4519.