CVE-2019-18839: Fudforum

Critical severity, CVSS 9.0. EPSS: 5.4% chance of exploitation in the next 30 days.

FUDForum 3.0.9 is vulnerable to Stored XSS via the nlogin parameter. This may result in remote code execution. An attacker can use a user account to fully compromise the system using a POST request. When the admin visits the user information, the payload will execute. This will allow for PHP files to be written to the web root, and for code to execute on the remote server.

Affected products

• Fudforum Fudforum: version 3.0.9 only

Published 2019-11-13. Last modified 2026-06-17.