CVE-2025-63064 is a stored Cross-site Scripting (XSS) vulnerability identified in the ashanjay EventON WordPress plugin, affecting versions up to and including 4.9.12. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, allowing malicious scripts to be stored and later executed in the context of users visiting the affected pages. Stored XSS is particularly dangerous because the malicious payload persists on the server and is delivered to multiple users without requiring repeated attacker interaction. This can lead to session hijacking, theft of cookies or credentials, unauthorized actions performed on behalf of users, defacement of websites, or redirection to malicious sites. The vulnerability does not require authentication to exploit, increasing its risk profile. Although no public exploits have been reported yet, the widespread use of EventON for event management on WordPress sites makes this a significant threat. The absence of a CVSS score suggests that the vulnerability is newly published and pending further analysis, but the nature of stored XSS vulnerabilities typically warrants a high severity rating. The vulnerability was reserved in late October 2025 and published in December 2025, indicating recent discovery and disclosure. No official patches or mitigation links were provided at the time of publication, so organizations must proactively implement defensive measures.

For European organizations, the impact of CVE-2025-63064 can be substantial, especially for those relying on EventON for event management on WordPress platforms. Successful exploitation could lead to unauthorized access to user sessions, data theft, and manipulation of event information, undermining trust and potentially causing reputational damage. The confidentiality of user data, including personal and event-related information, could be compromised. Integrity of the website content and event data may be altered or defaced, disrupting business operations and communications. Availability could be indirectly affected if attackers use the vulnerability to inject scripts that cause denial of service or redirect users away from legitimate services. Given the plugin’s role in managing events, disruptions could impact marketing, sales, and customer engagement activities. The threat is particularly relevant for sectors with high reliance on online event management, such as education, entertainment, and corporate services. Additionally, regulatory compliance risks arise under GDPR if personal data is exposed due to exploitation. The lack of known exploits currently reduces immediate risk but does not eliminate the potential for future attacks.

European organizations should take immediate steps to mitigate the risk posed by CVE-2025-63064. First, monitor the vendor’s official channels for patches or updates addressing this vulnerability and apply them promptly once available. In the absence of an official patch, implement strict input validation and output encoding on all user-supplied data related to EventON event creation and display. Employ a robust Content Security Policy (CSP) to restrict the execution of unauthorized scripts and reduce the impact of potential XSS payloads. Regularly audit and sanitize existing event data to remove any malicious scripts that may have been injected. Enable Web Application Firewalls (WAFs) with rules targeting XSS attack patterns to provide an additional layer of defense. Conduct security awareness training for administrators and content creators to recognize and prevent injection of malicious content. Monitor web server and application logs for unusual activities indicative of exploitation attempts. Finally, consider isolating or limiting the use of EventON on critical systems until the vulnerability is fully remediated.