CVE-2026-3109

low-risk
Published 2026-03-26

Mattermost Plugins versions <=11.4 10.11.11.0 fail to validate webhook request timestamps which allows an attacker to corrupt Zoom meeting state in Mattermost via replayed webhook requests. Mattermost Advisory ID: MMSA-2026-00584

Do I need to act?

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0.05% 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 2.2/10 Low
NETWORK / HIGH complexity
14
/ 100
low-risk
Severity 9/34 · Low
Exploitability 0/34 · Minimal
Exposure 5/34 · Minimal