CVE-2026-91181

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

CVE-2026-91181: Incorrect Authorization

Mattermost versions 11.9.x = 11.9.0, 11.8.x = 11.8.4, 11.7.x = 11.7.7, 10.11.x = 10.11.22 Fail to sanitize Team objects returned by the data retention teams endpoint which allows an authenticated user holding only the read-only Data Retention Policy permission to obtain a private team's secret...

SUSE CVE-2026-4274

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in the handling of API requests to /api/v1/teams/id when using a public-only access token. An attacker can retrieve private team repository metadata and private team activity feed entries by sending API requests...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in the handling of API requests to /api/v1/teams/id when using a public-only access token. An attacker can retrieve private team repository metadata and private team activity feed entries by sending API requests...

PT-2026-63298

Name of the Vulnerable Software and Affected Versions Gitea version 1.26.2 Description The /api/v1/teams/id API routes fail to correctly enforce the public-only access token restriction. A public-only token is designed to limit API access to public repositories and organizations; however, these...

Missing Authorization

Overview github.com/mattermost/mattermost/server/v8/channels/api4 is a platform for secure collaboration across the entire software development lifecycle Affected versions of this package are vulnerable to Missing Authorization via the scheme teams API endpoint. An attacker can access private tea...

EUVD-2026-43340

Mattermost versions 11.7.x = 11.7.2, 10.11.x = 10.11.19 fail to sanitize team objects returned by the scheme teams endpoint, which allows a user with the User Manager role to obtain invite links for private teams and use them to join or share access to those teams via the scheme teams API...

CVE-2026-9820

Mattermost versions 11.7.x <= 11.7.2 and 10.11.x

CVE-2026-2458

Mattermost versions 11.3.x = 11.3.0, 11.2.x = 11.2.2, 10.11.x = 10.11.10 fail to properly validate team membership when searching channels which allows a removed team member to enumerate all public channels within a private team via the channel search API endpoint.. Mattermost Advisory ID:...

GHSA-G7FP-CQJ5-X8HF Mattermost has an Incorrect Authorization issue

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

Mattermost has an Incorrect Authorization issue

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization in the membership synchronization process. An attacker can gain unauthorized access to an entire private team by sending crafted membership synchronization messages from a remote cluster that trigger team...

CVE-2026-4274

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

CVE-2026-4274 Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

CVE-2026-4274

Mattermost CVE-2026-4274 affects multiple release lines: 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, and 11.3.x

CVE-2026-4274 Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

CVE-2026-4274

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

CVE-2026-4274 Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

PT-2026-28642

Name of the Vulnerable Software and Affected Versions Mattermost versions 10.11.0 through 10.11.10 Mattermost versions 11.2.0 through 11.2.2 Mattermost versions 11.3.0 through 11.3.1 Mattermost versions 11.4.0 Description The software does not properly restrict team-level access when processing...