CVE-2025-50042 is a stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the WordPress plugin "WP Register Profile With Shortcode" developed by aviplugins.com. This vulnerability exists due to improper neutralization of user-supplied input during web page generation, allowing malicious scripts to be stored and subsequently executed in the context of other users' browsers. Specifically, the flaw affects all versions of the plugin up to and including version 3.6.1. Exploitation requires an attacker with at least low privileges (PR:L) to submit crafted input that is not properly sanitized or encoded before being rendered on web pages generated by the plugin. The vulnerability has a CVSS v3.1 base score of 6.5, indicating a medium severity level. The vector string (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L) shows that the attack can be performed remotely over the network with low attack complexity, requires privileges (likely a registered user), and user interaction (a victim must view the malicious content). The scope is changed (S:C), meaning the vulnerability affects resources beyond the vulnerable component, potentially impacting the entire web application. The impact includes limited confidentiality, integrity, and availability losses, as the attacker can execute arbitrary scripts in victim browsers, potentially stealing session tokens, performing actions on behalf of users, or defacing content. No known exploits are currently reported in the wild, and no patches or updates have been linked yet, indicating that mitigation may rely on vendor updates or manual intervention. Stored XSS vulnerabilities are particularly dangerous in WordPress environments due to the wide user base and the potential for privilege escalation or persistent compromise through malicious payloads embedded in user profiles or forms generated by the plugin.

For European organizations using WordPress sites with the WP Register Profile With Shortcode plugin, this vulnerability poses a significant risk to user data confidentiality and site integrity. Attackers could exploit the stored XSS to hijack user sessions, steal sensitive information, or manipulate site content, leading to reputational damage, regulatory non-compliance (e.g., GDPR violations due to data leakage), and potential financial losses. The scope change in the vulnerability means that the impact could extend beyond the plugin itself, affecting other parts of the website or integrated systems. Organizations with customer-facing portals or membership sites using this plugin are especially vulnerable, as attackers can target logged-in users to perform unauthorized actions. The requirement for user interaction (victim viewing malicious content) means phishing or social engineering could be used to increase exploitation success. Given the medium severity and the lack of known exploits, the threat is moderate but should be addressed promptly to prevent escalation or exploitation in targeted attacks. The vulnerability also increases the attack surface for supply chain attacks if exploited by adversaries targeting European enterprises relying on WordPress infrastructure.

1. Immediate mitigation should include disabling or removing the WP Register Profile With Shortcode plugin until a vendor patch is available. 2. Implement strict Content Security Policy (CSP) headers to restrict the execution of inline scripts and reduce the impact of XSS payloads. 3. Employ Web Application Firewalls (WAFs) with custom rules to detect and block malicious input patterns targeting the plugin's endpoints. 4. Conduct thorough input validation and output encoding on all user-supplied data, especially in user profile fields and shortcode-generated content, as a temporary manual fix if plugin code access is possible. 5. Monitor web server and application logs for suspicious activities related to user input submissions and unusual script executions. 6. Educate users about phishing risks since user interaction is required for exploitation. 7. Regularly audit installed WordPress plugins for vulnerabilities and maintain an inventory to prioritize patching. 8. Once a patch is released by aviplugins.com, apply it promptly and verify remediation through penetration testing focused on XSS vectors. 9. Consider isolating or sandboxing the affected plugin's functionality to limit scope impact until fully resolved.