CVE-2026-9162 Details
Description
Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to invalidate cached authentication state for active WebSocket connections during global session revocation, which allows a user with an existing WebSocket connection to remain authenticated and continue receiving real-time events until the cached session expires or the client reconnects.. Mattermost Advisory ID: MMSA-2026-00664
A vulnerability exists in Mattermost versions 11.7.x through 11.7.0, 11.6.x through 11.6.2, 11.5.x through 11.5.5, and 10.11.x through 10.11.17. The issue arises because these versions fail to properly invalidate cached authentication states for active WebSocket connections when a global session is revoked. As a result, users with existing WebSocket connections can remain authenticated and continue to receive real-time events until the cached session expires or the client reconnects.
Users can upgrade to Mattermost versions 11.8.0, 11.7.3, 11.6.4, or 10.11.20 to address this vulnerability.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jun 22, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://mattermost.com/security-updates | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-613 | Insufficient Session Expiration | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| mattermost mattermost server | >= 10.11.0, < 10.11.18 >= 11.5.0, < 11.5.6 >= 11.6.0, < 11.6.3 >= 11.7.0, < 11.7.1 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 23, 2026 | Initial Analysis | [email protected] |
| Jun 22, 2026 | CVE Modified | CISA-ADP |
| Jun 22, 2026 | New CVE Received | [email protected] |