4.3
MEDIUM CVSS 3.1
CVE-2026-9162
Global session revocation does not invalidate active WebSocket connections
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

INFO

Published Date :

June 22, 2026, 1:36 p.m.

Last Modified :

June 22, 2026, 1:36 p.m.

Remotely Exploit :

Yes !

Source :

Mattermost
Affected Products

The following products are affected by CVE-2026-9162 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 9302f53e-dde5-4bf3-b2f2-a83f91ac0eee
CVSS 3.1 MEDIUM MITRE-CVE
Solution
Update Mattermost to a patched version to properly invalidate cached authentication state.
  • Update Mattermost to a version that addresses this authentication issue.
  • Ensure cached sessions are invalidated after global revocation.
  • Restart WebSocket services if necessary.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-9162 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.