library/DBTech/Security/Action/Sessions.php in DragonByte vBSecurity 3.x through 3.3.0 for vBulletin 3 and vBulletin 4 allows self-XSS via $session['user_agent'] in the "Login Sessions" feature.
https://www.dragonbyte-tech.com/threads/security-bulletin-low-vbsecurity-for-vbulletin-3-vbulletin-4-partial-xss.22534/
Source: Mitre, NVD
Published: 2018-06-19
Updated: 2026-06-17
Base Score: 4.3
Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N
Severity: Medium
Base Score: 6.1
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS: 0.00301