CVE-2026-3109: Missing timestamp validation in Zoom webhook handler

Published Mar 26, 2026
·
Updated

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

Affected Software

2 affected components
Mattermost Mattermost Zoom Plugin<=11.4, =10.11.11.0
Mattermost Mattermost Server>=10.11.0<10.11.12

Remediation

Information

Update Mattermost Plugins to versions 11.5.0, 10.11.12 or higher.

Event History

Mar 26, 2026
CVE Published
via MITRE·04:28 PM
Data Sourced
via MITRE·04:28 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·05:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-3109?

CVE-2026-3109 is considered a high-severity vulnerability due to the potential for an attacker to manipulate zoom meeting states.

2

How do I fix CVE-2026-3109?

To remediate CVE-2026-3109, update the Mattermost Zoom plugin to versions higher than 11.4 or versions different than 10.11.11.0.

3

What are the potential impacts of CVE-2026-3109?

The potential impacts of CVE-2026-3109 include unauthorized access to and control over Zoom meeting states in Mattermost.

4

Which versions of the Mattermost Zoom plugin are affected by CVE-2026-3109?

CVE-2026-3109 affects Mattermost Zoom plugin versions 11.4 and 10.11.11.0 and older.

5

Is there a way to prevent CVE-2026-3109 exploitation?

Preventing exploitation of CVE-2026-3109 can be achieved by implementing proper timestamp validation in webhook handlers.

Company

Resources

Contact

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