CVE-2024-39837 Malicious remote can create arbitrary channels

What is CVE-2024-39837?

CVE-2024-39837 is a low-severity missing authorization vulnerability in Mattermost Mattermost Server, published on 1 Aug 2024. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

Mattermost versions 9.9.x <= 9.9.0, 9.5.x <= 9.5.6 fail to properly restrict channel creation which allows a malicious remote to create arbitrary channels, when shared channels were enabled.

Weakness: CWE-284

Which versions are affected by CVE-2024-39837?

19 open source packages ship an affected version, including github.com/mattermost/mattermost/server/v8, mattermost and github.com/mattermost/mattermost-server. It affects 1 product.

Products include Mattermost Mattermost Server.

How do I fix CVE-2024-39837?

Upgrade github.com/mattermost/mattermost/server/v8 to a fixed version for your release line: 8.0.0-20240626164322-c758cecaf30c, 9.5.7 or 9.9.1.

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

Is CVE-2024-39837 being exploited?

There is no known exploitation of CVE-2024-39837 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 BIT-mattermost-2024-39837, GHSA-vvpg-55p7-5h8w, GO-2024-3032.