CVE-2026-7184

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-7184

Mattermost CVE-2026-7184 affects Mattermost versions 11.6.x up to 11.6.1, 11.5.x up to 11.5.4, and 10.11.x up to 10.11.15. The issue is a failure to sanitize the Remote Cluster API response on PATCH operations, allowing authenticated users with the {{manage_secure_connections}} permission to obta...

CVE-2026-7184 Mattermost Remote Cluster PATCH API Leaks Authentication Tokens

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

EUVD-2026-36500

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-7184 Mattermost Remote Cluster PATCH API Leaks Authentication Tokens

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-7184 Mattermost Remote Cluster PATCH API Leaks Authentication Tokens

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

PT-2026-48940

Name of the Vulnerable Software and Affected Versions Mattermost versions 11.6.x through 11.6.1 Mattermost versions 11.5.x through 11.5.4 Mattermost versions 10.11.x through 10.11.15 Description Insufficient sanitization of the Remote Cluster API response during PATCH operations allows...

CVE-2026-7184: Insertion of Sensitive Information Into Sent Data

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-4273

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a craft...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

Mattermost Server 10.11.x <= 10.11.13 / 11.5.x <= 11.5.1 Multiple Vulnerabilities (MMSA-2026-00570 / MMSA-2026-00575 / MMSA-2026-00582 / MMSA-2026-00622)

The version of Mattermost Server installed on the remote host is affected by multiple vulnerabilities: - Mattermost fails to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an...

Incorrect Authorization

Overview Affected versions of this package are vulnerable to Incorrect Authorization via the membership sync process. An attacker can remove users from any channel, including private channels, by sending crafted membership sync messages from a remote cluster that is not authorized to access the...

GHSA-8H9W-W78C-VVR3 Mattermost does not verify remote cluster channel access when processing shared channel membership removals

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

GHSA-HQPJ-F3JH-29VX Mattermost doesn't validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a craft...

Mattermost doesn't validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a craft...

Mattermost does not verify remote cluster channel access when processing shared channel membership removals

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-4273

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a craft...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-4273 Insufficient token rotation validation in remote cluster invite confirmation

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a craft...

CVE-2026-4273

Mattermost contains an insufficient validation flaw in remote cluster invite confirmation. Versions affected: 11.5.x ≤ 11.5.1 and 10.11.x ≤ 10.11.13. The RefreshedToken is not properly checked against the original invite token, allowing an authenticated attacker to bypass token rotation and reuse...