CVE-2026-3471

Name: CVE-2026-3471
Creator: NVD / NIST
Published: 2026-05-18T09:16:22.847+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.5/10EPSS 0.18%

Last modified Jun 17, 2026

CVE-2026-3471 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent an invalid URL from loading in a pop-up window in the Mattermost Desktop App which allows a malicious server owner to repeated crash the application via calling {{window.open('javascript:alert()');}}. Mattermost Advisory ID: MMSA-2026-00618. EPSS estimates a 0.18% chance of exploitation in the next 30 days.

Description

Mattermost Desktop App versions <=6.1 6.0.1 5.4.13.0 fail to prevent an invalid URL from loading in a pop-up window in the Mattermost Desktop App which allows a malicious server owner to repeated crash the application via calling {{window.open('javascript:alert()');}}. Mattermost Advisory ID: MMSA-2026-00618

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.18%

8.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-939

Affected Software

Vendor	Product	Versions
Mattermost	Mattermost Desktop	<= 5.4.13.0
Mattermost	Mattermost Desktop	>= 6.0.0, <= 6.0.1
Mattermost	Mattermost Desktop	>= 6.1.0, < 6.2.0

References

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

Timeline

Published: May 18, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-3471?

How severe is CVE-2026-3471?

CVE-2026-3471 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.18% probability of exploitation in the next 30 days.

How do I fix CVE-2026-3471?

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-2026-3471?

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

Scan your code now

Source: NVD / NIST