CVE-2024-2446 Denial of service in Mattermost

What is CVE-2024-2446?

CVE-2024-2446 is a medium-severity denial of service vulnerability in Mattermost Mattermost Server, published on 15 Mar 2024. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

Mattermost versions 8.1.x before 8.1.10, 9.2.x before 9.2.6, 9.3.x before 9.3.2, and 9.4.x before 9.4.3 fail to limit the number of @-mentions processed per message, allowing an authenticated attacker to crash the client applications of other users via large, crafted messages.

Weakness: CWE-770, CWE-400

Which versions are affected by CVE-2024-2446?

1 open source package ship an affected version, including mattermost. It affects 1 product.

Products include Mattermost Mattermost Server.

How do I fix CVE-2024-2446?

Upgrade mattermost to a fixed version for your release line: 8.1.10, 9.2.6, 9.3.2 or 9.4.3.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2024-2446 being exploited?

There is no known exploitation of CVE-2024-2446 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-2024-2446, GHSA-x6jw-w885-qwpc.