CVE-2026-9820

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.7.0 through 11.7.2 Mattermost versions 10.11.0 through 10.11.19

Description The software fails to sanitize team objects returned by the 'scheme teams' endpoint. This allows a user with the User Manager role to obtain invite links for private teams and subsequently join or share access to those teams via the 'scheme teams' API endpoint.

Recommendations Update Mattermost versions 11.7.0 through 11.7.2 to a version newer than 11.7.2. Update Mattermost versions 10.11.0 through 10.11.19 to a version newer than 10.11.19.