CVE-2026-44559 Open WebUI: Missing Access Check on Channel Members Endpoint for Standard Channels

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the GET /api/v1/channels/id/members endpoint only checks membership for group and dm channel types lines 467-469. For standard channels — including private ones — there is no...

Open WebUI security vulnerabilities

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted WebUI under open source. Versions of Open WebUI prior to 0.9.5 contained security vulnerabilities. These vulnerabilities stemmed from insecure direct object reference vulnerabilities in the channel functionality. The...

Missing Authorization

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Missing Authorization in the getchannelmembersbyid process. An attacker can retrieve the list of users, including their IDs, names, emails, roles, and profile images, associated with a private channel by maki...

GHSA-C7WP-3QH5-55PV Open WebUI Missing Access Check on Channel Members Endpoint for Standard Channels

Missing Access Check on Channel Members Endpoint for Standard Channels Affected Component Channel members listing endpoint: - backend/openwebui/routers/channels.py lines 445-507, getchannelmembersbyid Affected Versions Current main branch and likely all versions with the channels feature...

Open WebUI Missing Access Check on Channel Members Endpoint for Standard Channels

Missing Access Check on Channel Members Endpoint for Standard Channels Affected Component Channel members listing endpoint: - backend/openwebui/routers/channels.py lines 445-507, getchannelmembersbyid Affected Versions Current main branch and likely all versions with the channels feature...

PT-2026-39276

Name of the Vulnerable Software and Affected Versions Open WebUI versions prior to 0.9.0 Description An issue exists in the 'GET /api/v1/channels/id/members' endpoint where membership checks are only performed for group and dm channel types. For standard channels, including private ones, the syst...

CVE-2026-2578

Mattermost versions 11.3.x = 11.3.0 fail to preserve the redacted state of burn-on-read posts during deletion which allows channel members to access unrevealed burn-on-read message contents via the WebSocket post deletion event.. Mattermost Advisory ID: MMSA-2026-00579...

Improper Access Control

github.com/mattermost/mattermost-server is vulnerable to improper access control. The vulnerability is due to insufficient validation of guest user permissions when adding channel members, which allows an attacker to add any team member to their private channels via the...

CVE-2025-55074 Channel member objects leak read status

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to enforce access permissions on the Agents plugin which allows other users to determine when users had read channels via channel member objects...

Unspecified Vulnerability in Mattermost (CNVD-2025-24795)

Mattermost is an open source collaboration platform from Mattermost, Inc. in the United States. Mattermost suffers from a security vulnerability that can be exploited by an attacker to cause guest users to add arbitrary team members to their private channels via the...

CVE-2025-10545

Mattermost versions 10.5.x = 10.5.10, 10.11.x = 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the /api/v4/channels/channelid/members endpoint...

CVE-2025-10545 Guest user can add unauthorized team users to private channels

Mattermost versions 10.5.x = 10.5.10, 10.11.x = 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the /api/v4/channels/channelid/members endpoint...

CVE-2025-10545 Guest user can add unauthorized team users to private channels

Mattermost versions 10.5.x = 10.5.10, 10.11.x = 10.11.2 fail to properly validate guest user permissions when adding channel members which allows guest users to add any team members to their private channels via the /api/v4/channels/channelid/members endpoint...

EUVD-2022-38139

Malicious code in bioql PyPI...

SUSE CVE-2025-1792

Mattermost versions 10.7.x = 10.7.0, 10.5.x = 10.5.3, 9.11.x = 9.11.12 fail to properly enforce access controls for guest users accessing channel member information, allowing authenticated guest users to view metadata about members of public channels via the channel members API endpoint...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via improper enforcement of permissions in the playbook run participant management process. An attacker can gain unauthorized access to sensitive channel content and escalate privileges by adding or removing user...

Mattermost security vulnerabilities

Mattermost is an open source collaboration platform from Mattermost, Inc. in the United States. Mattermost suffers from an information disclosure vulnerability that stems from insufficient authentication of channel members, which can be exploited by an attacker to cause sensitive information to b...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization through improper enforcement of channel member permissions for playbook run participants. An attacker without the 'Manage Channel Members' permission can add or remove users from public and private channels by...

Incorrect Authorization

Overview github.com/mattermost/mattermost-plugin-playbooks/server/app is a package for reliable and repeatable processes using checklists, automation, and retrospectives Affected versions of this package are vulnerable to Incorrect Authorization through improper enforcement of channel member...

Mattermost security vulnerabilities

Mattermost is an open source collaboration platform from Mattermost, Inc. in the United States. Mattermost suffers from a privilege issue vulnerability that stems from not properly enforcing channel member management privileges, which can be exploited by an attacker to enable unauthorized users t...