CVE-2026-9859 | Mattermost up to 10.11.21/11.7.6/11.8.3 channelId permission

A vulnerability labeled as problematic has been found in Mattermost up to 10.11.21/11.7.6/11.8.3. Impacted is an unknown function. The manipulation of the argument channelId results in permission issues.

This vulnerability is identified as CVE-2026-9859. The attack can be executed remotely. There is not any exploit available.

The affected component should be upgraded.VulDB Recent EntriesRead More