PT-2026-51345 · Mattermost · Mattermost

CVE-2026-8823

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Published

2026-06-22

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Updated

2026-06-22

CVSS v3.1

3.8

Low

VectorAV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L
Name of the Vulnerable Software and Affected Versions Mattermost version 11.7.0 Mattermost version 10.11.17
Description Insufficient validation of bot targets occurs when demoting users to guests. This allows a lower-privileged administrator to degrade arbitrary bot accounts through the 'demote-user' API endpoint.
Recommendations Update Mattermost version 11.7.0 to a newer version. Update Mattermost version 10.11.17 to a newer version. As a temporary workaround, restrict access to the 'demote-user' API endpoint for lower-privileged administrators.

Exploit

Fix

LPE

Incorrect Authorization

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Weakness Enumeration

Related Identifiers

CVE-2026-8823

Affected Products

Mattermost