CVE-2026-9693 Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite

Mattermost versions 10.11.x = 10.11.20, 11.7.x = 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via t...

CVE-2026-9693 Mattermost thread memberships persist after team removal, exposing private channel thread metadata on re-invite

Mattermost versions 10.11.x = 10.11.20, 11.7.x = 11.7.5 Mattermost fails to remove thread membership records when a user is removed from or leaves a team, which allows a previously removed user who is later re-invited to the team to view private channel thread root post content and metadata via t...

HackerOne: Minimum bounty of a private program is visible for users that were removed from the program

Hello, Privileged information is getting leaked to an unauthorized user in the json response of https://hackerone.com/reports/.json. In a team there can be many members, also roles are defined. But an x-member of the team is getting information which should not be visible to him. As I tested it o...