CVE-2026-6739
Mattermost: Delegated admins could patch protected default system roles
CVSS Score
6.7
EPSS Score
0.0%
EPSS Percentile
0th
Mattermost versions 11.6.x <= 11.6.1, 11.5.x <= 11.5.4, 10.11.x <= 10.11.15, 10.11.x <= 10.11.16 fail to require system-level permission when patching protected default system roles, which allows authenticated users with delegated user-management permissions to escalate privileges by altering built-in role permissions via the role patch API.. Mattermost Advisory ID: MMSA-2026-00656
| CWE | CWE-863 |
| Vendor | mattermost |
| Product | mattermost |
| Published | Jun 12, 2026 |
| Last Updated | Jun 12, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
Low
Affected Versions
Mattermost / Mattermost
11.6.0 ≤ 11.6.1 11.5.0 ≤ 11.5.4 10.11.0 ≤ 10.11.15 10.11.0 ≤ 10.11.16
Credits
NeganSpl01t