Is CVE-2004-0091 actively exploited?

No active exploitation of CVE-2004-0091 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2004-0091 be exploited remotely?

Yes. CVE-2004-0091 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2004-0091?

CVE-2004-0091 has a CVSS score of 4.3 (MEDIUM).

HOME VULNERABILITIESCVE-2004-0091

MEDIUM

CVE-2004-0091

NVD-CWE-OtherPublished: February 17, 2004· Updated: Jun 16, 2026

4.3

CVSS v3.1

Official Description

NOTE: this issue has been disputed by the vendor. Cross-site scripting (XSS) vulnerability in register.php for unknown versions of vBulletin allows remote attackers to inject arbitrary HTML or web script via the reg_site (or possibly regsite) parameter. NOTE: the vendor has disputed this issue, saying "There is no hidden field called 'reg_site', nor any $reg_site variable anywhere in the vBulletin 2 or vBulletin 3 source code or templates, nor has it ever existed. We can only assume that this vulnerability was found in a site running code modified from that supplied by Jelsoft.

NVD Source

Technical Analysis

CVE-2004-0091 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.