CVE-2025-9076

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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
6.5 MEDIUM
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
MattermostCNA
6.5 MEDIUM
NETWORK
LOW
HIGH
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
CISA-ADPADP
---
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Base Score
CVSS 3.x
EPSS Score
Percentile: 9%
VendorProductVersion
mattermostmattermost_server
10.10.0 ≤
𝑥
< 10.10.2
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://mattermost.com/security-updates