CVE-2026-24981: Visionary Core Object Injection Vulnerability

CVE-2026-24981 Overview

A critical deserialization of untrusted data vulnerability has been identified in the NooTheme Visionary Core WordPress plugin (noo-visionary-core). This vulnerability allows attackers to perform PHP Object Injection attacks, potentially leading to remote code execution, unauthorized data access, or complete site compromise. The vulnerability affects all versions of Visionary Core through version 1.4.9.

Critical Impact

Authenticated attackers with low privileges can exploit insecure deserialization to inject malicious PHP objects, potentially achieving remote code execution on affected WordPress installations.

Affected Products

• NooTheme Visionary Core plugin versions through 1.4.9
• WordPress installations running the vulnerable noo-visionary-core plugin
• Websites using themes dependent on Visionary Core functionality

Discovery Timeline

• 2026-03-25 - CVE CVE-2026-24981 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2026-24981

Vulnerability Analysis

This vulnerability stems from improper handling of serialized data within the Visionary Core plugin. When the plugin processes user-supplied input, it fails to properly validate or sanitize data before passing it to PHP's unserialize() function. This allows an authenticated attacker to inject arbitrary PHP objects into the application.

The attack requires network access and low-level authentication (such as a subscriber account), but does not require user interaction. Successful exploitation can result in complete compromise of confidentiality, integrity, and availability of the affected WordPress installation.

PHP Object Injection vulnerabilities are particularly dangerous in WordPress environments due to the presence of numerous "gadget chains" - existing class methods that can be chained together to achieve code execution when malicious objects are deserialized.

Root Cause

The root cause of CVE-2026-24981 is the use of PHP's native unserialize() function on user-controllable input without proper validation. CWE-502 (Deserialization of Untrusted Data) describes this class of vulnerability where applications deserialize data from untrusted sources without verifying its integrity or structure.

The plugin fails to implement safe deserialization practices, such as:

• Using JSON instead of PHP serialization for data transport
• Implementing allowlists for permitted classes during deserialization
• Validating serialized data signatures before processing

Attack Vector

The attack is conducted over the network and requires the attacker to have a low-privileged authenticated session on the WordPress site. The attacker crafts a malicious serialized PHP object payload containing references to classes available in the WordPress environment or installed plugins that have exploitable magic methods (__wakeup(), __destruct(), __toString(), etc.).

When this malicious payload is processed by the vulnerable deserialization routine, the PHP runtime instantiates the attacker-specified objects, triggering the magic methods and executing arbitrary code through available gadget chains.

For technical details on the specific exploitation mechanism, refer to the Patchstack WordPress Vulnerability Database.

Detection Methods for CVE-2026-24981

Indicators of Compromise

• Presence of serialized PHP data containing unexpected class names in request logs
• Unusual POST requests to WordPress endpoints associated with the Visionary Core plugin
• Unexpected file modifications or new files in the WordPress installation
• Anomalous process execution originating from the web server
• Database entries containing serialized objects with suspicious class references

Detection Strategies

• Monitor web server logs for requests containing serialized PHP data patterns (e.g., O: followed by class names)
• Implement Web Application Firewall (WAF) rules to detect and block PHP object injection payloads
• Deploy file integrity monitoring to detect unauthorized changes to WordPress core, plugin, and theme files
• Review authentication logs for creation of new low-privileged accounts that could be used for exploitation

Monitoring Recommendations

• Enable verbose logging for the Visionary Core plugin and associated WordPress actions
• Configure SIEM alerts for patterns indicative of deserialization attacks in web traffic
• Monitor for outbound connections from the web server that may indicate successful exploitation
• Implement runtime application self-protection (RASP) to detect object injection attempts

How to Mitigate CVE-2026-24981

Immediate Actions Required

• Audit WordPress installations to identify instances of the Visionary Core plugin at version 1.4.9 or earlier
• Disable or remove the noo-visionary-core plugin if it is not essential to site functionality
• Review user accounts and remove any unnecessary low-privileged accounts that could be leveraged for exploitation
• Implement additional authentication requirements for administrative functions
• Deploy WAF rules to block known PHP object injection patterns

Patch Information

Check the Patchstack vulnerability database for updates on patch availability from NooTheme. Until an official patch is released, implement the workarounds and mitigations described below.

Workarounds

• Remove or deactivate the Visionary Core plugin if it is not critical to site operations
• Implement strict input validation and sanitization at the application firewall level
• Restrict user registration to prevent attackers from creating accounts for exploitation
• Use security plugins that provide virtual patching capabilities for known WordPress vulnerabilities
• Consider migrating to an alternative theme framework that does not rely on the vulnerable plugin

# Configuration example - Disable the vulnerable plugin via WP-CLI
wp plugin deactivate noo-visionary-core --path=/var/www/html/wordpress

# List all users with subscriber or higher roles for audit
wp user list --role=subscriber --fields=ID,user_login,user_email --path=/var/www/html/wordpress