GHSA-FMQF-PMCM-8CX9 Mattermost doesn't validate user channel membership when attaching Mattermost posts as comments to Jira issues

Mattermost versions 11.1.x = 11.1.0, 11.0.x = 11.0.5, 10.12.x = 10.12.3, 10.11.x = 10.11.7 fails to validate user channel membership when attaching Mattermost posts as comments to Jira issues, which allows an authenticated attacker with access to the Jira plugin to read post content and attachmen...