Mattermost
CVE-2026-26230
LOW
Severity by source
AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
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
AnalysisAI
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.
Technical ContextAI
This vulnerability is classified as Incorrect Authorization (CWE-863).
RemediationAI
Monitor vendor advisories for patches. Apply mitigations such as network segmentation, access restrictions, and monitoring.
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Same weakness CWE-863 – Incorrect Authorization
View allSame technique Authentication Bypass
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External POC / Exploit Code
Leaving vuln.today