CVE-2025-47581 is a critical vulnerability identified in the Elbisnero WordPress Events Calendar Registration & Tickets plugin, specifically affecting versions up to 2.6.0. The vulnerability is classified under CWE-502, which pertains to Deserialization of Untrusted Data. This type of vulnerability arises when an application deserializes data from untrusted sources without sufficient validation, allowing attackers to inject malicious objects. In this case, the flaw enables Object Injection attacks, which can lead to remote code execution, privilege escalation, or other severe impacts on the affected system. The vulnerability has a CVSS 3.1 base score of 9.8, indicating a critical severity level. The vector metrics (AV:N/AC:L/PR:N/UI:N) show that the attack can be executed remotely over the network without any privileges or user interaction, making exploitation straightforward and highly dangerous. The scope is unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), meaning successful exploitation can lead to full system compromise. Although no known exploits are currently reported in the wild, the nature of the vulnerability and its ease of exploitation suggest that threat actors could develop exploits rapidly. The plugin is widely used for managing event registrations and ticketing on WordPress sites, which are common across many organizations, including those in Europe. The lack of an official patch at the time of publication increases the urgency for mitigation measures.

For European organizations, this vulnerability poses a significant risk, especially for those relying on WordPress for event management and ticketing through the Elbisnero plugin. Exploitation could lead to unauthorized access, data breaches involving sensitive customer or organizational information, defacement of websites, or disruption of event-related services. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR violations due to data breaches), and cause financial losses. Given the critical severity and ease of exploitation, attackers could leverage this vulnerability to establish persistent footholds within networks, potentially moving laterally to compromise other systems. Organizations in sectors such as event management, education, government, and cultural institutions that frequently use event calendar plugins are particularly at risk. Additionally, the absence of a patch means that organizations must rely on alternative mitigations to protect their environments until an official fix is released.

1. Immediate mitigation should include disabling or uninstalling the affected Elbisnero WordPress Events Calendar Registration & Tickets plugin until a security patch is available. 2. If disabling the plugin is not feasible, restrict access to the plugin’s functionalities via web application firewalls (WAFs) or by implementing strict IP whitelisting to limit exposure to trusted users only. 3. Monitor web server and application logs for unusual activity or signs of exploitation attempts, such as unexpected serialized data in requests. 4. Employ runtime application self-protection (RASP) or intrusion detection systems (IDS) that can detect and block deserialization attacks. 5. Keep WordPress core and all other plugins/themes updated to reduce the attack surface. 6. Prepare for rapid deployment of patches by subscribing to vendor advisories and security mailing lists. 7. Conduct security awareness training for administrators managing WordPress sites to recognize and respond to suspicious activities. 8. Consider implementing Content Security Policy (CSP) and other browser security headers to mitigate the impact of potential exploitation.