CVE-2025-60081 identifies a critical vulnerability in the PDF for Contact Form 7 plugin developed by add-ons.org, specifically versions up to and including 6.3.4. The vulnerability is due to deserialization of untrusted data, a common security flaw where the application processes serialized objects without proper validation or sanitization. This flaw allows attackers to perform object injection attacks by crafting malicious serialized payloads that, when deserialized by the plugin, can execute arbitrary code or manipulate application logic. The plugin integrates with Contact Form 7, a widely used WordPress form plugin, to generate PDFs from form submissions. Since WordPress powers a significant portion of websites globally, and Contact Form 7 is among the most popular form plugins, this vulnerability has a broad potential attack surface. The lack of a CVSS score indicates that the vulnerability is newly disclosed and not yet fully assessed, but the nature of deserialization vulnerabilities typically implies high risk due to the possibility of remote code execution. No known exploits are currently reported in the wild, but the vulnerability is published and thus available to attackers. The vulnerability affects all versions up to 6.3.4, and no patch links are currently provided, indicating that a fix may still be pending. The vulnerability was reserved in late September 2025 and published in December 2025, suggesting recent discovery. The plugin’s insecure deserialization mechanism is the root cause, and exploitation requires an attacker to submit crafted data to the vulnerable plugin component, potentially via form submissions or other input vectors. This vulnerability threatens confidentiality, integrity, and availability of affected systems, as successful exploitation could lead to full system compromise.

For European organizations, this vulnerability poses a significant risk, especially for those using WordPress websites with the Contact Form 7 plugin and the PDF add-on. Exploitation could lead to remote code execution, allowing attackers to take control of web servers, steal sensitive data, deface websites, or use compromised servers as a foothold for further attacks within corporate networks. This could impact customer data confidentiality, disrupt business operations, and damage organizational reputation. Given the widespread use of WordPress in Europe, including government, education, and private sectors, the potential impact is broad. Attackers could exploit this vulnerability to deploy malware, ransomware, or conduct espionage. The lack of authentication requirements for exploitation increases risk, as attackers may not need valid credentials. Additionally, the vulnerability could be leveraged in supply chain attacks if exploited on service providers hosting multiple client sites. The absence of known exploits currently provides a window for proactive defense, but the publication of the vulnerability increases the likelihood of future attacks. Organizations with public-facing WordPress sites that handle sensitive or regulated data are particularly at risk, as exploitation could lead to regulatory penalties under GDPR if personal data is compromised.

Immediate mitigation should focus on monitoring and restricting access to vulnerable endpoints. Organizations should audit their WordPress installations to identify the presence of the PDF for Contact Form 7 plugin and verify the version. Until a patch is released, consider disabling or removing the plugin to eliminate the attack surface. Employ Web Application Firewalls (WAFs) with rules to detect and block suspicious serialized payloads or unusual POST requests targeting form submission endpoints. Implement strict input validation and sanitization at the application level where possible. Monitor logs for anomalous activity indicative of exploitation attempts, such as unexpected serialized data or errors related to deserialization. Limit permissions of the web server user to reduce impact if exploitation occurs. Stay informed about vendor updates and apply patches promptly once available. Additionally, consider isolating WordPress instances in segmented network zones to contain potential breaches. Conduct regular security assessments and penetration testing focusing on deserialization vulnerabilities. Educate developers and administrators about the risks of insecure deserialization and secure coding practices. Finally, maintain robust backup and incident response plans to recover quickly if exploitation occurs.