Unauthenticated PHP Object Injection in FC United Theme by Patchstack
CVE-2026-66565

9.8CRITICAL

Key Information:

Vendor

WordPress
Status
Fc United
Vendor
CVE Published:
10 October 2026

What is CVE-2026-66565?

The FC United Theme for WordPress is susceptible to an unauthenticated PHP Object Injection vulnerability, which affects versions up to 1.1.1. This vulnerability allows an attacker to manipulate the PHP object expecting certain inputs, potentially leading to arbitrary code execution or other malicious actions. Users of this theme should update to the latest version to mitigate the risk associated with this security flaw.

Affected Version(s)

FC United <= 1.1.1

References

https://patchstack.com/database/wordpress/theme/fcunited/...
vdb-entry

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

João Pedro S Alcântara (Kinorth) | Patchstack Bug Bounty Program
.