CVE-2026-8823

Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-privileged administrator to degrade arbitrary bot accounts via the standard demote-user API.. Mattermost Advisory ID: MMSA-2026-00669

CVSS v3 3.8 LOW

3.8^/10

CVSS v3 : LOW

Vector :

Exploitability : 1.2 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://mattermost.com/security-updates	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:mattermost:mattermost_server::::::::
	cpe:2.3:a:mattermost:mattermost_server::::::::

History

26 Jun 2026, 16:39

Type	Values Removed	Values Added
First Time		Mattermost mattermost Server Mattermost
CPE		cpe:2.3:a:mattermost:mattermost_server::::::::
References	~~() https://mattermost.com/security-updates -~~	() https://mattermost.com/security-updates - Vendor Advisory

22 Jun 2026, 16:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-06-22 16:16

Updated : 2026-06-26 16:39

NVD link : CVE-2026-8823

Mitre link : CVE-2026-8823

CVE.ORG link : CVE-2026-8823

JSON object : View

Products Affected

mattermost

mattermost_server

CWE

CWE-863

Incorrect Authorization

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