A critical unauthenticated PHP Object Injection vulnerability in the Happyforms WordPress plugin requires immediate patching to version 1.26.14 or later.

This vulnerability stems from the insecure deserialization of untrusted user input by the plugin. Unauthenticated attackers can inject malicious objects, which may lead to full system compromise if suitable POP chains are present in the underlying environment.

With a CVSS score of 9.8, this flaw represents a major security risk. Exploitation could result in the destruction of site data, unauthorized access to form submissions, and long-term persistence, severely impacting business operations and data privacy.

Immediate Action: Update the Happyforms plugin to version 1.26.14 or the latest available release.

Proactive Monitoring: Monitor server logs for suspicious requests involving serialized objects and audit plugin settings for unauthorized changes.

Compensating Controls: Implement WAF filtering to block requests containing serialized PHP objects to prevent exploitation until patching is complete.

Public Exploit Available: False

Administrators must prioritize the update to version 1.26.14. The severity of this vulnerability necessitates prompt action to protect the integrity of the WordPress site and the data collected through the Happyforms plugin.