CVE-2026-26230 LOW

CVE-2026-26230: Team Admin Privilege Escalation to Demote Members to Guest

Vendor Mattermost
Product Mattermost
Weakness CWE-863 · Incorrect authorization
Published March 16, 2026
Last update March 17, 2026
View on NVD All CVEs

CVSS base score

3.8/10
Attack vector Network
Attack complexity Low
Privileges required High
User interaction None
Confidentiality Low
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N

What the vulnerability does

01Description

Mattermost versions 10.11.x <= 10.11.10 fail to properly validate permission requirements in the team member roles API endpoint which allows team administrators to demote members to guest role. Mattermost Advisory ID: MMSA-2025-00531

Key dates

02Disclosure timeline

March 16, 2026 CVE published
March 17, 2026 Record updated