CVE-2026-27769
Low
Description
Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API.. Mattermost Advisory ID: MMSA-2026-00603
SeverityLow
CVSS2.7
Exploit probability—
Product
Mattermost Server
PublishedApr 15, 2026
First seenApr 15, 2026
Weakness typeCWE-862Missing authorization
How to fix
Update
- mattermost mattermost_server10.11.13 or later
- github.com/mattermost/mattermost-server8.0.0-20260316060126-bc1a2b34b1f9 or later
Vendor advisories
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| mattermost mattermost_server | 10.11.0 ≤ v < 10.11.13 | 10.11.13 |
| github.com/mattermost/mattermost-serverGo | 8.0.0-20250721062209-4952acea88ce ≤ v < 8.0.0-20260316060126-bc1a2b34b1f9, No range specified | 8.0.0-20260316060126-bc1a2b34b1f9 |
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