CVE-2026-27769

low-risk
Published 2026-04-15

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

Do I need to act?

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0.03% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
2
CVSS 2.7/10 Low
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

Mattermost

References (1)

Vendor Advisory https://mattermost.com/security-updates
19
/ 100
low-risk
Severity 14/34 · Moderate
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal