PT-2026-51345 · Mattermost · Mattermost

Published

2026-06-22

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Updated

2026-06-22

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CVE-2026-8823

CVSS v3.1

3.8

Low

VectorAV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:L
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

Fix

Incorrect Authorization

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Weakness Enumeration

Related Identifiers

CVE-2026-8823

Affected Products

Mattermost