CVE-2026-93851 Path traversal in Mattermost Agents plugin mention reminder allows plugin replacement via crafted post

Mattermost versions 11.9.x = 11.9.1, 11.8.x = 11.8.5, 11.7.x = 11.7.10 fail to validate the target post ID in the Agents plugin's mention reminder component, which allows an authenticated user who can post in a channel visible to a system administrator to cause the administrator's browser to send...