PT-2026-41655

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.5.x through 11.5.1 Description An issue exists where channel membership is not verified during the processing of AI-assisted message rewrites. This allows an authenticated attacker to read the content of threads in priva...

CVE-2026-45385 Open WebUI: An IDOR vulnerability exists in the update_message_by_id API endpoint

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, an IDOR vulnerability exists in the Channels feature of Open WebUI, allowing any channel member to modify messages sent by other members including administrators within the same...

EUVD-2026-30619

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the isuserchannelmember function checks whether a ChannelMember row exists but does not check the isactive field. When a user is deactivated from a group or DM channel removed by the...

CVE-2026-44561

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the isuserchannelmember function checks whether a ChannelMember row exists but does not check the isactive field. When a user is deactivated from a group or DM channel removed by the...

GHSA-HMGR-67HW-J2CQ Open WebUI: Deactivated Channel Members Retain Full Access to Group/DM Channels

Deactivated Channel Members Retain Full Access to Group/DM Channels Affected Component Channel membership authorization check: - backend/openwebui/models/channels.py lines 663-673, isuserchannelmember - Used at 15 locations in backend/openwebui/routers/channels.py Affected Versions Current main...

Open WebUI: Deactivated Channel Members Retain Full Access to Group/DM Channels

Deactivated Channel Members Retain Full Access to Group/DM Channels Affected Component Channel membership authorization check: - backend/openwebui/models/channels.py lines 663-673, isuserchannelmember - Used at 15 locations in backend/openwebui/routers/channels.py Affected Versions Current main...

Improper Authorization

github.com/mattermost/mattermost-server is vulnerable to improper authorization. The vulnerability is due to insufficient validation of team membership permissions in the Add Channel Member API, which allows an attacker to exploit the API endpoint to access user metadata and channel membership...

PT-2026-39278

Name of the Vulnerable Software and Affected Versions Open WebUI versions prior to 0.9.0 Description Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. An issue exists where the is user channel member function verifies the existence of a membership...

Improper Access Control

github.com/mattermost/mattermost-server is vulnerable to improper access control. The vulnerability is due to failure to validate user channel membership when attaching posts to Jira issues, which allows an authenticated attacker with Jira plugin access to read post content and attachments from...

BIT-DISCOURSE-2026-32618 Discourse: Unauthorized channel membership inference via excluded_memberships_channel_id

Discourse is an open-source discussion platform. From versions 2026.1.0 to before 2026.1.3, and 2026.2.0 to before 2026.2.2, there is possible channel membership inference from chat user search without authorization. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0...

CVE-2026-32618

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, there is possible channel membership inference from chat user search without authorization. This issue has been patched in...

CVE-2026-32618

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, there is possible channel membership inference from chat user search without authorization. This issue has been patched in...

CVE-2026-32618 Discourse: Unauthorized channel membership inference via excluded_memberships_channel_id

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, there is possible channel membership inference from chat user search without authorization. This issue has been patched in...

CVE-2026-32618

Discourse (open-source discussion platform) has a channel membership inference vulnerability affecting versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, where chat user search could reveal channel membership without authorizat...

CVE-2026-32618

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, there is possible channel membership inference from chat user search without authorization. This issue has been patched in...

CVE-2026-32618 Discourse: Unauthorized channel membership inference via excluded_memberships_channel_id

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, there is possible channel membership inference from chat user search without authorization. This issue has been patched in...

CVE-2026-32618 Discourse: Unauthorized channel membership inference via excluded_memberships_channel_id

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, there is possible channel membership inference from chat user search without authorization. This issue has been patched in...

PT-2026-29309

Name of the Vulnerable Software and Affected Versions Discourse versions 2026.1.0 through 2026.1.2, 2026.2.0 through 2026.2.1, and 2026.3.0. Description A flaw exists in Discourse that may allow unauthorized channel membership inference from chat user search. This issue does not require...

SUSE CVE-2025-13767

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...

SUSE CVE-2025-14350

Mattermost versions 11.1.x = 11.1.2, 10.11.x = 10.11.9, 11.2.x = 11.2.1 fail to properly validate team membership when processing channel mentions which allows authenticated users to determine the existence of teams and their URL names via posting channel shortlinks and observing the...