CVE-2025-69370: Capella Object Injection Vulnerability

CVE-2025-69370 Overview

CVE-2025-69370 is a critical Insecure Deserialization vulnerability affecting the ThemeGoods Capella WordPress theme. This vulnerability allows unauthenticated attackers to perform PHP Object Injection attacks by exploiting improper handling of serialized data. The vulnerability exists in Capella theme versions up to and including 2.5.5.

Critical Impact

Successful exploitation enables attackers to inject arbitrary PHP objects, potentially leading to remote code execution, data theft, or complete site compromise on vulnerable WordPress installations.

Affected Products

• ThemeGoods Capella WordPress Theme versions through 2.5.5
• WordPress installations using vulnerable Capella theme versions

Discovery Timeline

• 2026-02-20 - CVE CVE-2025-69370 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2025-69370

Vulnerability Analysis

This vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). The ThemeGoods Capella theme fails to properly validate or sanitize serialized data before passing it to PHP's unserialize() function. When user-controlled data is deserialized without adequate security checks, an attacker can craft malicious serialized payloads that instantiate arbitrary PHP objects with attacker-controlled properties.

The vulnerability is exploitable over the network without requiring authentication or user interaction, making it highly dangerous for publicly accessible WordPress sites. Upon successful exploitation, attackers can leverage existing PHP classes with dangerous magic methods (__wakeup(), __destruct(), __toString()) to achieve arbitrary code execution, file manipulation, or database access.

Root Cause

The root cause of this vulnerability is the unsafe use of PHP's unserialize() function on user-supplied input without proper validation. The Capella theme processes serialized data from untrusted sources without implementing allowlist-based class restrictions or input sanitization, allowing attackers to inject malicious object chains.

Attack Vector

The attack is network-based and requires no authentication or privileges. An attacker can submit a specially crafted serialized PHP object through vulnerable theme functionality. When the application deserializes this payload, it triggers the instantiation of PHP objects with attacker-controlled properties. By chaining together gadgets (existing classes with exploitable magic methods), the attacker can achieve various malicious outcomes including remote code execution.

The exploitation typically follows this pattern: the attacker identifies a deserialization entry point in the theme, constructs a PHP Object Injection payload using available gadget chains (potentially from WordPress core, plugins, or the theme itself), and submits the payload to trigger code execution or other malicious actions.

Detection Methods for CVE-2025-69370

Indicators of Compromise

• Unusual serialized data patterns in HTTP request parameters containing O: or a: prefixes
• Suspicious PHP error logs indicating object instantiation failures or unexpected class loading
• Web server logs showing requests with base64-encoded or URL-encoded serialized payloads
• Unexpected file modifications or new files created in the WordPress directory structure

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block serialized PHP object patterns in incoming requests
• Monitor for unusual process spawning from PHP or web server processes that may indicate code execution
• Review access logs for requests containing suspicious serialized data patterns to theme-related endpoints
• Deploy endpoint detection solutions to identify post-exploitation behavior such as webshell deployment

Monitoring Recommendations

• Enable verbose logging for WordPress and the Capella theme to capture deserialization-related errors
• Configure intrusion detection systems to alert on PHP Object Injection payload signatures
• Monitor file integrity of the WordPress installation directory for unauthorized modifications
• Set up alerts for anomalous outbound network connections from the web server

How to Mitigate CVE-2025-69370

Immediate Actions Required

• Update the ThemeGoods Capella theme to a patched version immediately if one is available from the vendor
• If no patch is available, consider temporarily disabling or replacing the Capella theme
• Implement WAF rules to block requests containing serialized PHP object patterns
• Audit WordPress installations for signs of compromise before and after remediation

Patch Information

The vulnerability affects Capella theme versions up to and including 2.5.5. Website administrators should check the Patchstack WordPress Vulnerability Report for the latest patch availability and remediation guidance from ThemeGoods.

Workarounds

• Deploy a Web Application Firewall with rules to filter serialized PHP object patterns in request data
• Implement PHP configuration hardening by restricting unserialize() through allowed_classes parameter where possible
• Use WordPress security plugins that can detect and block object injection attempts
• Consider migrating to an alternative WordPress theme if a timely patch is not released

# Example WAF rule pattern to block PHP serialized objects
# Block requests containing PHP serialized object patterns
# Pattern: O:[0-9]+:"[a-zA-Z_]
SecRule ARGS "@rx O:[0-9]+:\"[a-zA-Z_]" "id:100001,phase:2,deny,status:403,msg:'PHP Object Injection Attempt Blocked'"