CVE-2026-27769
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…
Does this matter?
Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own.
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
- CVSS 3.1
- 2.7 LOWCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.17% probability · 6th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-862
- Affected
- mattermost/mattermost server
- Source
- responsibledisclosure@mattermost.com
References
- https://mattermost.com/security-updatesVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.