CVE-2026-3471 Details
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
A denial-of-service vulnerability has been identified in the Mattermost Desktop App, affecting versions 6.1, 6.0.1, and 5.4.13.0. The issue arises because the application fails to block invalid URLs from opening in a pop-up window. This flaw allows a malicious server owner to repeatedly crash the application by using a JavaScript alert as the URL payload.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed May 18, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://mattermost.com/security-updates | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-939 | Improper Authorization in Handler for Custom URL Scheme | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| mattermost mattermost desktop | <= 5.4.13.0 >= 6.0.0, <= 6.0.1 >= 6.1.0, < 6.2.0 |
CPE
Remediation
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Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| Jun 5, 2026 | Initial Analysis | [email protected] |
| May 18, 2026 | New CVE Received | [email protected] |