CyberRota Analysis
This is a medium severity vulnerability with a CVSS score of 4.3. It may be remotely exploitable.
CVE
CVE-2026-28759
Severity
MEDIUM
CVSS
4.3
EPSS
0.15%
Original NVD Description
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, including private channels, via crafted membership sync messages targeting channels the remote cluster is not authorized to access. Mattermost Advisory ID: MMSA-2026-00576
Related CVEs
Other vulnerabilities affecting the same vendor(s)