CVE-2026-18795

EUVD-2026-102813
Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to enforce DM/GM check on server side which allows an authenticated user to quarantine a post belonging to DM or GM via direct API call.. Mattermost Advisory ID: MMSA-2026-00756
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
6.4 MEDIUM
NETWORK
HIGH
LOW
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L
Base Score
CVSS 3.x
EPSS Score
Percentile: 3.85%
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 11.10.0
CNA
mattermostmattermost
11.7.0 ≤
𝑥
≤ 11.7.9
CNA
mattermostmattermost
11.9.0 ≤
𝑥
≤ 11.9.1
CNA
mattermostmattermost
11.8.0 ≤
𝑥
≤ 11.8.5
CNA
Common Weakness Enumeration
References
https://mattermost.com/security-updates