CVE-2026-3471
Opening a window with {{javascript:alert()}} as URL causes crash in the Mattermost Desktop App
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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
| CWE | CWE-939 |
| Vendor | mattermost |
| Product | mattermost |
| Published | May 18, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
Mattermost / Mattermost
0 ≤ 6.0.1 0 ≤ 5.4.13
Credits
game0v3r