# CVE-2026-40757: Mikado-Themes Château PHP Object Injection

Source: https://junglewise.ai/threats/cve-2026-40757-mikado-themes-chateau-php-object-injection  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-17. Updated: 2026-06-20  
License: CC BY 4.0 with a link back

CVE-2026-40757 · Severity: high · CVSS 8.1 · Published 2026-06-17

The Château theme for WordPress is vulnerable to a security flaw that allows unauthorized attackers to inject malicious code into a website. This theme is used to control the visual layout and functionality of a site; an exploit could lead to full site takeover, data theft, or the site being used to spread malware. Business operations could be severely impacted through loss of site control and reputation damage.

Vendors: [Mikado-Themes](https://junglewise.ai/threats/vendors/mikado-themes).

## Quick answers

**Is CVE-2026-40757 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-40757 being exploited in the wild.

**How severe is CVE-2026-40757?** High severity, with a CVSS score of 8.1, published 17 June 2026.

**Which products and versions are affected?** Mikado-Themes Château <= 1.2.1.

**Is there a fix for CVE-2026-40757?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-40757 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-40757?** Check whether you run Mikado-Themes Château at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A PHP Object Injection vulnerability exists in the Château theme for WordPress in versions up to and including 1.2.1. The flaw stems from the deserialization of untrusted data (CWE-502), which allows an unauthenticated remote attacker to inject arbitrary PHP objects. If a suitable Property-Oriented Programming (POP) chain is present in the environment, this can lead to remote code execution, SQL injection, or arbitrary file deletion. The attack vector is network-based and requires no user interaction, though the CVSS complexity is rated as high, likely due to the requirement of a usable POP chain. A patch is available in version 1.3.

## Affected products

- Mikado-Themes Château <= 1.2.1

## Timeline

- 2026-02-24: other: Reported by Denver Jackson
- 2026-04-20: disclosed: Vulnerability published by Patchstack
- 2026-06-17: advisory: NVD published date

## References

- [https://wordpress.org/themes](https://wordpress.org/themes)
- [https://patchstack.com/database/wordpress/theme/chateau/vulnerability/wordpress-chateau-theme-1-2-1-php-object-injection-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/theme/chateau/vulnerability/wordpress-chateau-theme-1-2-1-php-object-injection-vulnerability?_s_id=cve)