Mattermost versions 10.10.x <= 10.10.1 fail to properly sanitize user data during shared channel membership synchronization, which allows malicious or compromised remote clusters to access sensitive user information via unsanitized user objects. This vulnerability affects Mattermost Server instances with shared channels enabled.
Fix
Patch, vendor advisory and mitigation references on NVD 1
- https://mattermost.com/security-updates Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 6.5 · mattermostNVD modified 2026-10-19 17:10
Affected (CPE criteria) 1
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*
References 1
- https://mattermost.com/security-updates Vendor Advisory