CVE-2025-66073 is a vulnerability in the Cozmoslabs WP Webhooks WordPress plugin, affecting all versions up to and including 3.3.8. The issue arises from the unsafe deserialization of untrusted data, which allows an attacker to perform object injection. Deserialization vulnerabilities occur when untrusted input is processed by a program expecting serialized objects, enabling attackers to craft malicious payloads that manipulate program logic or state. In this case, the WP Webhooks plugin accepts serialized data through its webhook endpoints without sufficient validation or sanitization, allowing remote attackers to inject crafted objects. This can lead to unauthorized modification of plugin behavior, potential data leakage, or integrity violations within the WordPress environment. The vulnerability is exploitable remotely over the network without requiring authentication or user interaction, increasing its risk profile. However, the CVSS vector indicates that the impact on confidentiality and integrity is limited, and availability is unaffected. No known exploits have been reported in the wild as of the publication date. The plugin is widely used in WordPress sites to automate workflows via webhooks, making it a valuable target for attackers aiming to compromise site functionality or data. The lack of a patch link suggests that a fix may not yet be publicly available, emphasizing the need for interim mitigations.

For European organizations, the impact of CVE-2025-66073 can be significant, especially for those relying on WordPress sites with the WP Webhooks plugin installed. Successful exploitation could allow attackers to manipulate webhook-triggered workflows, potentially leading to unauthorized data access or modification within the WordPress environment. This could compromise the confidentiality and integrity of sensitive information, including customer data, business logic, or internal communications automated via webhooks. Although availability is not directly impacted, the integrity breaches could disrupt business processes or damage organizational reputation. Sectors such as e-commerce, media, and government agencies in Europe that use WordPress extensively are at higher risk. Additionally, organizations subject to strict data protection regulations like GDPR must consider the compliance implications of any data compromise resulting from this vulnerability. The remote and unauthenticated nature of the exploit increases the likelihood of scanning and exploitation attempts, making timely mitigation critical.

1. Monitor Cozmoslabs and WordPress plugin repositories closely for the release of an official patch addressing CVE-2025-66073 and apply it immediately upon availability. 2. Until a patch is released, implement web application firewall (WAF) rules to detect and block suspicious serialized data patterns or unusual webhook payloads targeting the WP Webhooks endpoints. 3. Restrict access to webhook endpoints by IP whitelisting or requiring authentication tokens to limit exposure to trusted sources only. 4. Conduct an audit of all webhook configurations to ensure they do not process untrusted or unnecessary data. 5. Employ runtime application self-protection (RASP) tools if available to detect and prevent deserialization attacks dynamically. 6. Educate development and security teams about the risks of deserialization vulnerabilities and encourage secure coding practices for handling serialized data. 7. Regularly review WordPress plugin usage and remove or replace plugins that are no longer maintained or pose security risks. 8. Implement comprehensive logging and monitoring of webhook activity to detect anomalous behavior indicative of exploitation attempts.