CVE-2026-3636

EUVD-2026-31428
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to sanitize team member data when returned via API to users without elevated permissions which allows a user without permissions to get data about team members roles via invoking various team API endpoints.. Mattermost Advisory ID: MMSA-2026-00626
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
MattermostCNA
4.3 MEDIUM
NETWORK
LOW
LOW
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 8%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_server
10.11.0 ≤
𝑥
< 10.11.15
mattermostmattermost_server
11.4.0 ≤
𝑥
< 11.4.5
mattermostmattermost_server
11.5.0 ≤
𝑥
< 11.5.4
mattermostmattermost_server
11.6.0 ≤
𝑥
< 11.6.1
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 11.6.0
CNA
mattermostmattermost
11.5.0 ≤
𝑥
≤ 11.5.3
CNA
mattermostmattermost
11.4.0 ≤
𝑥
≤ 11.4.4
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.14
CNA