The vulnerability identified as CVE-2025-64353 affects the Polylang plugin for WordPress, specifically versions up to 3.7.3. It is a deserialization of untrusted data vulnerability, which means that the plugin improperly handles serialized data input from untrusted sources. Deserialization vulnerabilities occur when an application deserializes data without sufficient validation, allowing attackers to inject malicious objects. In this case, the vulnerability enables object injection, which can lead to remote code execution, privilege escalation, or data manipulation depending on the context and the payload delivered. Polylang is a popular plugin used to create multilingual WordPress sites, making it a high-value target. The vulnerability was published on October 31, 2025, but no CVSS score has been assigned yet, and no known exploits are currently active in the wild. However, the technical nature of the flaw and the widespread use of Polylang increase the risk of exploitation once proof-of-concept code becomes available. The lack of patches at the time of publication means organizations must be vigilant and implement interim mitigations. The vulnerability arises from unsafe deserialization practices, a common and dangerous security flaw that can compromise the confidentiality, integrity, and availability of affected systems.

For European organizations, the impact of CVE-2025-64353 can be severe. Many businesses, government agencies, and e-commerce platforms in Europe rely on WordPress and plugins like Polylang to manage multilingual content. Successful exploitation could allow attackers to execute arbitrary code on web servers, leading to data breaches, website defacement, or full system compromise. This could result in loss of customer trust, regulatory penalties under GDPR, and operational disruption. The vulnerability could also be leveraged to pivot into internal networks or deploy ransomware. Given the critical role of multilingual websites in European commerce and public services, the threat extends beyond individual websites to broader economic and reputational damage. The absence of known exploits currently provides a window for proactive defense, but the risk of rapid exploitation once exploit code is publicly available is high.

Organizations should immediately inventory their WordPress installations to identify the use of the Polylang plugin and its version. Until an official patch is released, apply the following mitigations: disable or restrict access to the plugin if feasible; implement web application firewall (WAF) rules to detect and block suspicious serialized payloads or unusual POST requests targeting Polylang endpoints; enforce strict input validation and sanitization on all user inputs; monitor logs for anomalies indicative of deserialization attacks; isolate WordPress servers from critical internal networks to limit lateral movement; and prepare for rapid deployment of patches once available. Additionally, consider using security plugins that detect and prevent object injection attacks. Regular backups and incident response readiness are essential to minimize damage in case of compromise.