CVE-2026-27045: WooCommerce Infinite Scroll Vulnerability

CVE-2026-27045 Overview

CVE-2026-27045 is a Deserialization of Untrusted Data vulnerability affecting the WooCommerce Infinite Scroll plugin (sb-woocommerce-infinite-scroll) developed by sbthemes for WordPress. This vulnerability enables PHP Object Injection attacks, allowing authenticated attackers with low-level privileges to inject malicious serialized objects into the application. When these objects are deserialized, they can trigger dangerous operations through magic methods in the PHP class autoload chain.

Critical Impact

This vulnerability allows authenticated attackers to achieve arbitrary code execution, data manipulation, or denial of service by exploiting insecure deserialization of user-controlled data within the WooCommerce Infinite Scroll plugin.

Affected Products

• WooCommerce Infinite Scroll plugin versions through 1.6.2
• WordPress installations with the sb-woocommerce-infinite-scroll plugin active
• WooCommerce-enabled sites using the infinite scroll functionality

Discovery Timeline

• 2026-03-25 - CVE-2026-27045 published to NVD
• 2026-03-26 - Last updated in NVD database

Technical Details for CVE-2026-27045

Vulnerability Analysis

This vulnerability stems from CWE-502 (Deserialization of Untrusted Data), a dangerous pattern where user-supplied data is passed directly to PHP's unserialize() function without proper validation. The WooCommerce Infinite Scroll plugin fails to adequately sanitize input before deserialization, creating an attack surface for PHP Object Injection.

When a PHP application deserializes attacker-controlled data, the instantiated objects can trigger magic methods such as __destruct(), __wakeup(), or __toString(). If a gadget chain exists within the application or its dependencies (including WordPress core, WooCommerce, or other plugins), attackers can chain these methods to achieve arbitrary code execution, file system access, or database manipulation.

The network-accessible nature of this vulnerability combined with low privilege requirements makes it particularly dangerous for WordPress/WooCommerce installations.

Root Cause

The root cause of CVE-2026-27045 is the direct use of PHP's unserialize() function on user-controlled input without implementing proper validation or allowlist filtering. The plugin accepts serialized data from authenticated users and processes it without verifying the integrity or expected structure of the serialized payload.

WordPress environments are particularly susceptible to Object Injection vulnerabilities due to the extensive class library available through WordPress core, WooCommerce, and various installed plugins. These classes often contain magic methods that can be weaponized as part of a Property-Oriented Programming (POP) chain.

Attack Vector

The attack is executed over the network and requires only low-level authenticated access (such as a subscriber or customer account on the WordPress site). The attacker crafts a malicious serialized PHP object containing a carefully constructed payload designed to exploit available gadget chains.

The exploitation process involves identifying available PHP classes with exploitable magic methods, constructing a serialized payload that triggers the desired chain of operations upon deserialization, and submitting this payload through the vulnerable plugin endpoint. Depending on the available gadget chains in the target environment, successful exploitation can lead to remote code execution, arbitrary file operations, or complete site compromise.

Detection Methods for CVE-2026-27045

Indicators of Compromise

• Unusual HTTP requests containing serialized PHP objects (look for patterns like O: followed by class names)
• Unexpected plugin activity or configuration changes in WordPress
• Anomalous PHP error logs referencing deserialization or unfamiliar class instantiation
• Evidence of unauthorized file modifications in WordPress directories

Detection Strategies

• Monitor web application firewall (WAF) logs for requests containing serialized PHP payloads
• Implement input validation logging to detect attempts to pass serialized data to plugin endpoints
• Deploy endpoint detection and response (EDR) solutions to identify post-exploitation behavior
• Review WordPress audit logs for suspicious authenticated user activity

Monitoring Recommendations

• Enable detailed PHP error logging and monitor for deserialization-related errors
• Configure SIEM rules to alert on patterns matching PHP serialized object syntax in request bodies
• Implement file integrity monitoring for WordPress core, plugin, and theme directories
• Monitor for unexpected outbound network connections from the web server

How to Mitigate CVE-2026-27045

Immediate Actions Required

• Deactivate and remove the WooCommerce Infinite Scroll plugin (sb-woocommerce-infinite-scroll) immediately if running version 1.6.2 or earlier
• Audit WordPress user accounts and remove any unnecessary authenticated users
• Review server logs for evidence of exploitation attempts
• Scan the WordPress installation for signs of compromise using security plugins or external tools

Patch Information

No official patch has been confirmed at the time of this analysis. Site administrators should monitor the Patchstack vulnerability database for updates regarding a security fix from sbthemes. Until a patched version is available, the plugin should remain deactivated.

Workarounds

• Disable the WooCommerce Infinite Scroll plugin until a patched version is released
• Implement Web Application Firewall (WAF) rules to block requests containing serialized PHP objects
• Restrict authenticated user access to only trusted individuals
• Consider using alternative infinite scroll solutions that have been audited for security
• Apply principle of least privilege to all WordPress user accounts

# Configuration example
# WordPress wp-config.php hardening - disable file modifications
define('DISALLOW_FILE_EDIT', true);
define('DISALLOW_FILE_MODS', true);

# .htaccess rule to block common serialized object patterns
# Add to WordPress root .htaccess
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{QUERY_STRING} (O:|a:|s:) [NC]
RewriteRule .* - [F,L]
</IfModule>