CVE-2025-55757 is a reflected cross-site scripting (XSS) vulnerability identified in the VirtueMart component for Joomla, affecting versions 1.0.0 through 4.4.10. This vulnerability arises from improper neutralization of user-supplied input during web page generation, classified under CWE-79. An unauthenticated attacker can craft a malicious URL containing script code that, when visited by a victim, causes the browser to execute the injected script within the context of the vulnerable website. This can lead to theft of session cookies, defacement, or redirection to malicious sites. The vulnerability requires no authentication but does require user interaction (clicking a crafted link). The CVSS v3.1 base score is 6.1, indicating a medium severity level, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), user interaction required (UI:R), scope changed (S:C), and impacts on confidentiality and integrity (C:L, I:L) but no impact on availability (A:N). No public exploits or patches are currently available, increasing the urgency for proactive mitigation. Given VirtueMart's widespread use in Joomla-based e-commerce sites, this vulnerability poses a risk to online stores and their customers, potentially leading to data theft or reputational damage.

For European organizations, especially those operating e-commerce platforms using Joomla with the VirtueMart component, this vulnerability can lead to significant risks including theft of user credentials, session hijacking, and unauthorized actions performed on behalf of users. Confidentiality and integrity of user data are at risk, which can result in regulatory non-compliance under GDPR if personal data is compromised. The reflected XSS can also be leveraged for phishing attacks targeting customers, damaging brand reputation and customer trust. While availability is not directly impacted, the indirect effects such as loss of customer confidence and potential legal consequences can be severe. Organizations with high traffic Joomla-based e-commerce sites in Europe are particularly vulnerable, as attackers may exploit this flaw to target large user bases. The lack of available patches and known exploits means organizations must act proactively to mitigate risk.

European organizations should immediately audit their Joomla installations to identify the use of VirtueMart versions 1.0.0 through 4.4.10. Until an official patch is released, implement strict input validation and output encoding on all user-supplied data within the VirtueMart component to prevent script injection. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts. Use web application firewalls (WAFs) with rules designed to detect and block reflected XSS attack patterns targeting VirtueMart URLs. Educate users and administrators about the risks of clicking suspicious links. Monitor web server logs for unusual query strings or repeated attempts to exploit XSS. Plan for timely patching once updates become available from the vendor. Additionally, consider isolating or restricting access to vulnerable components if feasible, and conduct regular security assessments to detect similar vulnerabilities.