CVE-2025-20086

Name of the Vulnerable Software and Affected Versions Mattermost versions 10.2.x through 10.2.0 Mattermost versions 9.11.x through 9.11.5 Mattermost versions 10.0.x through 10.0.3 Mattermost versions 10.1.x through 10.1.3

Description The issue arises from the failure to properly validate post properties, allowing a malicious authenticated user to cause a crash via a malicious post. This can be exploited by an authenticated user to disrupt the service.

Recommendations For versions 10.2.x through 10.2.0, update to a version that properly validates post properties. For versions 9.11.x through 9.11.5, update to a version that properly validates post properties. For versions 10.0.x through 10.0.3, update to a version that properly validates post properties. For versions 10.1.x through 10.1.3, update to a version that properly validates post properties. As a temporary workaround, consider restricting access to post properties to minimize the risk of exploitation.