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
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mattermost | Mattermost | unaffected |
|
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Project Subscriptions
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Advisories
No advisories yet.
Fixes
Solution
Update Mattermost to versions 11.8.0, 11.7.1, 10.11.18 or higher.
Workaround
No workaround given by the vendor.
References
| Link | Providers |
|---|---|
| https://mattermost.com/security-updates |
|
History
Mon, 22 Jun 2026 15:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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 | |
| Title | User Manager can demote bot accounts to guest without bot-management permission | |
| Weaknesses | CWE-863 | |
| References |
| |
| Metrics |
cvssV3_1
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Projects
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MITRE
Status: PUBLISHED
Assigner: Mattermost
Published:
Updated: 2026-06-22T13:41:28.404Z
Reserved: 2026-05-18T10:05:31.691Z
Link: CVE-2026-8823
Vulnrichment
No data.
NVD
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Redhat
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OpenCVE Enrichment
No data.
Weaknesses