VDB
CVE-2026-15754
CVE-2026-15754
PUBLISHED
CVSS 4.2 MEDIUM
Reported by Mattermost · Published August 17, 2026
Mattermost versions 11.7.x <= 11.7.6, 11.8.x <= 11.8.3 The access control policy unassign endpoint fails to re-validate that each target channel still belongs to the requesting admin's team, which allows an authenticated team administrator to remove ABAC (attribute-based access control) policy assignments from channels outside their team via the policy unassign API after a channel has been moved to another team.. Mattermost Advisory ID: MMSA-2026-00718
Risk Scores
CVSS 3.1
4.2
CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:H/A:N
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Mattermost | Mattermost | 11.7.0, 11.8.0, 11.9.0 |
| Mattermost | Mattermost | 11.7.0, 11.8.0, 11.9.0 |
Timeline
- Aug 17, 2026 CVE Published
- Aug 17, 2026 CVE Updated
- Aug 22, 2026 Coalition ESS Score
- Aug 24, 2026 EPSS Score
References
- MMSA-2026-00718 vendor-advisory