Compliance Impact

The vulnerability in the WordPress Léonie Theme (versions 1.2.1 and below) allows unauthenticated PHP Object Injection, which can lead to code execution, SQL injection, path traversal, and denial of service attacks. Such security flaws can result in unauthorized access to sensitive data or disruption of services.

Because of these risks, organizations using affected versions may face challenges in maintaining compliance with data protection standards and regulations like GDPR and HIPAA, which require safeguarding personal and sensitive information against unauthorized access and ensuring system integrity.

Failure to patch this vulnerability could lead to data breaches or service interruptions, potentially resulting in regulatory penalties or loss of trust.

Useful 0 Not Useful 0

Executive Summary

CVE-2026-40758 is a high-priority PHP Object Injection vulnerability found in the WordPress Léonie Theme versions 1.2.1 and below.

This vulnerability allows unauthenticated attackers to inject malicious PHP objects, potentially enabling code injection, SQL injection, path traversal, denial of service, and other harmful actions if a suitable POP (Property Oriented Programming) chain exists.

It is classified under OWASP Top 10 A3: Injection and has a CVSS severity score of 8.1, indicating a high level of risk.

The issue affects versions up to 1.2.1 and is fixed in version 1.3.

Useful 0 Not Useful 0

Impact Analysis

This vulnerability can have severe impacts including unauthorized code execution, data breaches through SQL injection, unauthorized file access via path traversal, and denial of service attacks.

Because it requires no authentication to exploit, attackers can potentially compromise thousands of websites running vulnerable versions of the Léonie theme.

Such exploitation could lead to loss of data integrity, confidentiality, and availability of your website and its data.

Useful 0 Not Useful 0

Detection Guidance

The vulnerability affects the WordPress Léonie Theme versions 1.2.1 and below and is an unauthenticated PHP Object Injection flaw. Detection typically involves identifying if the vulnerable theme version is in use.

While no specific detection commands are provided, users can check the installed theme version on their WordPress site by running commands such as:

• Using WP-CLI to check the theme version: wp theme list --status=active
• Manually inspecting the theme's style.css file located in wp-content/themes/leonie/ for the version number.

Additionally, network detection might involve monitoring for attack patterns that exploit PHP Object Injection vulnerabilities, but no specific network commands or signatures are provided.

Useful 0 Not Useful 0

Mitigation Strategies

The immediate and recommended mitigation step is to update the WordPress Léonie Theme to version 1.3 or later, as this patched version resolves the vulnerability.

Until the update can be applied, Patchstack has issued a mitigation rule to block attacks exploiting this vulnerability. Applying such mitigation rules or firewall rules to block suspicious requests targeting the vulnerable theme is advised.

Because the vulnerability is unauthenticated and can be exploited remotely, prompt action is critical to prevent potential code injection, SQL injection, path traversal, denial of service, and other malicious activities.

Useful 0 Not Useful 0