CVE-2026-56055: RealHomes PHP Object Injection Vulnerability

CVE-2026-56055 Overview

CVE-2026-56055 is a PHP Object Injection vulnerability affecting the RealHomes WordPress theme in versions up to and including 4.5.3. The flaw arises from insecure deserialization of untrusted input, classified under [CWE-502]. An authenticated attacker with Subscriber-level privileges can inject crafted serialized PHP objects that trigger unintended method calls during object destruction or property access. Successful exploitation can lead to arbitrary code execution, data tampering, or full site compromise when a suitable gadget chain exists within the WordPress installation or its plugins.

Critical Impact
A low-privileged Subscriber account can leverage this deserialization flaw to compromise confidentiality, integrity, and availability of RealHomes-powered WordPress sites.

Affected Products

RealHomes WordPress theme versions 4.5.3 and earlier
WordPress installations using the vulnerable RealHomes theme
Sites permitting Subscriber-level user registration on RealHomes deployments

Discovery Timeline

2026-06-26 - CVE-2026-56055 published to NVD
2026-06-26 - Last updated in NVD database

Technical Details for CVE-2026-56055

Vulnerability Analysis

The RealHomes theme processes user-controllable input through PHP's unserialize() function without validating the source or content of the serialized data. When an authenticated Subscriber submits crafted input containing a serialized PHP object, the deserialization routine instantiates arbitrary classes available in the WordPress runtime. Magic methods such as __wakeup(), __destruct(), or __toString() execute during this process. Attackers chain these methods together using gadget chains sourced from WordPress core, other plugins, or Composer dependencies. The result is arbitrary code execution or file manipulation under the web server's privileges.

Root Cause

The root cause is unsafe PHP object deserialization [CWE-502]. RealHomes calls unserialize() on data reachable by low-privileged authenticated users without applying an allowed-classes filter or a signed integrity check. PHP's native serialization format preserves object types and properties, so any class autoloaded by WordPress becomes a candidate for a gadget chain. The absence of input validation and type restrictions permits attacker-controlled object graphs to enter the application state.

Attack Vector

Exploitation requires network access to the WordPress site and a valid Subscriber account, which is trivial to obtain on sites allowing public registration. The attacker submits a crafted request containing a serialized payload to an endpoint that deserializes user input. No user interaction is required beyond the attacker's own authenticated request. The scope remains unchanged, but confidentiality, integrity, and availability are all impacted at a high level.

See the Patchstack Vulnerability Report for additional technical context.

Detection Methods for CVE-2026-56055

Indicators of Compromise

Requests from authenticated Subscriber accounts containing serialized PHP patterns such as O: (object), a: (array), or s: (string) markers in POST bodies or query parameters
Unexpected file creation, modification, or execution in wp-content/ directories following Subscriber activity
Outbound network connections initiated by the PHP worker process to attacker-controlled hosts
New administrative users, altered options in wp_options, or unexpected scheduled tasks in wp_cron

Detection Strategies

Inspect HTTP request bodies for PHP serialization signatures targeting RealHomes theme endpoints
Correlate Subscriber-role authentications with subsequent file-write events on the web server
Deploy Web Application Firewall (WAF) rules that flag unserialize()-compatible payloads in user-submitted parameters
Enable PHP error and audit logging to capture deserialization exceptions and unexpected class instantiations

Monitoring Recommendations

Monitor RealHomes theme endpoints for anomalous POST volume from Subscriber accounts
Track WordPress audit logs for privilege changes, plugin activations, and theme file modifications
Alert on outbound connections from PHP-FPM or Apache worker processes to non-approved destinations
Baseline and monitor wp_options, wp_users, and wp_usermeta tables for unauthorized modifications

How to Mitigate CVE-2026-56055

Immediate Actions Required

Update the RealHomes theme to a version above 4.5.3 as soon as the vendor releases a patched release
Disable open user registration or restrict the default new-user role away from Subscriber where feasible
Audit existing Subscriber accounts and remove or disable unrecognized entries
Deploy WAF signatures that block serialized PHP payloads targeting RealHomes endpoints

Patch Information

Refer to the Patchstack Vulnerability Report for the authoritative patch status. At the time of publication, the advisory identifies versions 4.5.3 and earlier as vulnerable. Site administrators should upgrade to the fixed release published by the RealHomes vendor and verify integrity of theme files after upgrade.

Workarounds

Temporarily disable the RealHomes theme and switch to a default WordPress theme until the patch is applied
Restrict access to vulnerable endpoints using web server access controls or WAF rules
Apply virtual patching at the reverse proxy layer to strip or reject serialized PHP object payloads
Enforce least privilege by removing self-registration and requiring administrator approval for new accounts

bash

# Example ModSecurity rule to block PHP object serialization patterns in request bodies
SecRule REQUEST_BODY "@rx (?:^|[&=])[Oa]:\d+:\"" \
    "id:1005601,phase:2,deny,status:403,log,\
    msg:'Potential PHP Object Injection payload (CVE-2026-56055)',\
    tag:'attack-injection-php'"