CVE-2026-6062

EUVD-2026-38250
Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 Fail to validate channel ownership of an existing subscription before applying edits which allows an authenticated attacker to hijack subscriptions from channels they have no access to via a crafted PUT request to the subscription edit endpoint.. Mattermost Advisory ID: MMSA-2026-00650
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: 15.07%
Affected Products (NVD)
VendorProductVersion
mattermostmattermost_server
10.11.0 ≤
𝑥
< 10.11.18
mattermostmattermost_server
11.5.0 ≤
𝑥
< 11.5.6
mattermostmattermost_server
11.6.0 ≤
𝑥
< 11.6.3
mattermostmattermost_server
11.7.0 ≤
𝑥
< 11.7.1
𝑥
= Vulnerable software versions
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
mattermostmattermost
𝑥
≤ 11.7.0
CNA
mattermostmattermost
11.6.0 ≤
𝑥
≤ 11.6.2
CNA
mattermostmattermost
11.5.0 ≤
𝑥
≤ 11.5.5
CNA
mattermostmattermost
10.11.0 ≤
𝑥
≤ 10.11.17
CNA