Vulnerability · Published Jun 12, 2026 · Assigned by Mattermost
CVE-2026-7184Mattermost Remote Cluster PATCH API Leaks Authentication Tokens
Medium 6.5
In plain English
A medium-severity security flaw in Mattermost from Mattermost. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 {{manage_secure_connections}} permission to obtain remote cluster authentication tokens via a PATCH request to the remote cluster endpoint.. Mattermost Advisory ID: MMSA-2026-00662
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/mattermost/mattermost-server | 11.6.1 | GHSA-9p44-r552-4wp9 |
| Go | github.com/mattermost/mattermost-server | 11.5.5 | GHSA-9p44-r552-4wp9 |
| Go | github.com/mattermost/mattermost-server | 10.11.16 | GHSA-9p44-r552-4wp9 |
| Go | github.com/mattermost/mattermost-server | 10.11.16+incompatible, 11.5.5+incompatible, 11.6.1+incompatible | GO-2026-6282 |
| Go | github.com/mattermost/mattermost-server/v5 | no fix listed | GO-2026-6282 |
| Go | github.com/mattermost/mattermost-server/v6 | no fix listed | GO-2026-6282 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20260428142921-bd8fc9222672 | GO-2026-6282 |
| Go | github.com/mattermost/mattermost/server/v8 | 8.0.0-20260428142921-bd8fc9222672 | GHSA-9p44-r552-4wp9 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 11.6.0 – through 11.6.111.5.0 – through 11.5.410.11.0 – through 10.11.15 |
Weakness: CWE-201 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
References
- MMSA-2026-00662 vendor-advisory