CVE-2025-6226

EUVD-2025-21867
Mattermost versions 10.5.x <= 10.5.6, 10.8.x <= 10.8.1, 10.7.x <= 10.7.3, 9.11.x <= 9.11.16 fail to verify authorization when retrieving cached posts by PendingPostID which allows an authenticated user to read posts in private channels they don't have access to via guessing the PendingPostID of recently created posts.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
MattermostCNA
6.5 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 14%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_server
9.11.0 ≤
𝑥
< 9.11.17
mattermostmattermost_server
10.5.0 ≤
𝑥
< 10.5.7
mattermostmattermost_server
10.7.0 ≤
𝑥
< 10.7.4
mattermostmattermost_server
10.8.0 ≤
𝑥
< 10.8.2
𝑥
= Vulnerable software versions
Common Weakness Enumeration
References
https://mattermost.com/security-updates