CVE-2026-3109

Name: CVE-2026-3109
Creator: NVD / NIST
Published: 2026-03-26T17:16:41.967+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 2.2/10EPSS 0.29%

Last modified Jun 17, 2026

CVE-2026-3109 is a low-severity vulnerability rated 2.2/10 on the CVSS scale. 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. EPSS estimates a 0.29% chance of exploitation in the next 30 days.

Description

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

Metrics

CVSS 3.1

2.2/10

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L

EPSS Probability

0.29%

20.7th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-754

Affected Software

Vendor	Product	Versions
Mattermost	Mattermost Server	>= 10.11.0, < 10.11.12

References

https://mattermost.com/security-updatesVendor Advisory

Timeline

Published: Mar 26, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-3109?

How severe is CVE-2026-3109?

CVE-2026-3109 has a CVSS score of 2.2/10 (LOW severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3109?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-3109?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST