CVE-2026-12081 in Contact Form 7 Plugin
Summary
by MITRE • 07/13/2026
The Database for Contact Form 7, WPforms, Elementor forms WordPress plugin before 1.5.2 does not restrict the PHP classes allowed when unserializing an attacker-supplied form-field value, allowing unauthenticated users to inject arbitrary PHP objects that are instantiated when an administrator views the stored entry. This is an incomplete fix of CVE-2025-7384 and CVE-2026-2599, whose deserialization paths were hardened while the entry-editor file-field path was missed.
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Analysis
by VulDB Data Team • 07/13/2026
This vulnerability exists within the Database for Contact Form 7 plugin for WordPress affecting versions prior to 1.5.2, representing a critical security flaw that enables unauthenticated attackers to execute arbitrary PHP code through object injection during form field deserialization processes. The issue stems from insufficient restrictions on PHP classes allowed during the unserialization of attacker-controlled data, specifically within the entry editor functionality where form field values are processed and stored. The vulnerability operates through a deserialization attack vector that allows malicious actors to inject specially crafted serialized objects into form fields, which are then instantiated when administrators view the stored entries in the WordPress admin interface.
The technical implementation of this flaw involves the plugin's failure to implement proper class whitelisting during PHP unserialization operations within the entry editor component. When an administrator accesses the stored form submissions, the plugin processes these entries through the vulnerable deserialization path without validating or restricting which PHP classes can be instantiated from the serialized data. This creates a remote code execution pathway where attackers can inject malicious objects such as Phantoms or other exploit classes that execute arbitrary code on the target server with the privileges of the WordPress installation. The vulnerability represents a classic object injection flaw that aligns with CWE-502, which specifically addresses unsafe deserialization of untrusted data.
The operational impact of this vulnerability is severe and potentially devastating for affected WordPress installations, as it allows attackers to achieve full system compromise without requiring authentication or administrative privileges. Once an attacker successfully injects malicious serialized objects into form fields, any administrator who views the stored entries becomes a victim of the exploitation process, making this attack particularly dangerous in environments where multiple administrators have access to the admin interface. The vulnerability's persistence means that even after the initial injection, the malicious code continues to execute whenever the affected entries are accessed, potentially allowing for ongoing system compromise, data exfiltration, or further attack propagation through the compromised server.
This vulnerability represents an incomplete remediation of previous security issues CVE-2025-7384 and CVE-2026-2599, where similar deserialization flaws were addressed in other components of the plugin but not in the entry-editor file-field processing path. The oversight demonstrates a common pattern in software security where fixes are applied to some attack vectors while leaving others unaddressed, creating continued risk for users who may have updated to versions that seemingly resolved previous issues. Security researchers should consider this vulnerability as part of a broader exploitation landscape that includes similar deserialization weaknesses affecting WordPress plugins, and organizations should implement comprehensive patch management strategies that cover all known vulnerable components within their plugin ecosystem.
The mitigation approach requires immediate installation of the patched version 1.5.2 or later, which implements proper class restrictions during unserialization operations within the entry editor functionality. Organizations should also consider implementing additional security measures such as monitoring for suspicious form submissions, restricting administrator access to only necessary personnel, and applying web application firewalls that can detect and block malicious serialized object patterns. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1505.003 for deserialization of untrusted data and should be addressed through both immediate patching and long-term security hardening measures including input validation, output encoding, and principle of least privilege access controls within WordPress environments.