PHP Object Injection in WordPress Search Regex Plugin

The Search Regex plugin for WordPress is vulnerable to PHP Object Injection in version 3.5 via deserialization of untrusted input in the replace_all function. This allows authenticated attackers, with subscriber-level access and above, to inject a PHP Object. The additional presence of a POP chain allows attackers to execute code.

Casky was already ahead

This CVE exploits attack patterns that Casky's 447matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.

Analysis

CVE-2026-104932 exploits unsafe PHP deserialization in the Search Regex plugin's replace_all function, allowing authenticated attackers with subscriber-level permissions to inject malicious PHP objects. This vulnerability is particularly dangerous because it bridges the gap between low-privilege access and arbitrary code execution through PHP's Property-Oriented Programming (POP) chains. WordPress sites running Search Regex version 3.5 are at risk, especially those with permissive user role assignments. The CVSS score of 8 reflects the high severity: while authentication is required, the low privilege threshold and direct code execution capability make this a critical issue for multi-user WordPress installations.

Casky's 447 matching skills leverage Claude's extended reasoning to detect the attack patterns across MITRE techniques TA0001 (Initial Access), TA0043 (Reconnaissance), and TA0002 (Execution). Practitioners using Casky would identify suspicious activity through skill detections focused on: unauthorized object deserialization attempts in plugin function calls, POP chain gadget chains being instantiated through user-controlled input, and unexpected code execution following authentication events by low-privilege accounts. The platform's skills would flag patterns like unusual serialized data in replace_all function parameters, instantiation of dangerous PHP classes within the Search Regex namespace, and subsequent process execution or file modifications tied to subscriber-level user actions—enabling teams to correlate initial reconnaissance activity with exploitation attempts before code reaches execution stage.

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Casky Risk Score

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EPSS Probability

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Shodan Exposure

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GreyNoise Signal

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Composite risk scoring from EPSS, CISA KEV, Shodan, and GreyNoise — 21 security APIs correlated into a single Casky Risk Score. Coming in Casky Pro. Join early access →

447 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-104932.

Abuse of Public-Facing API: Mobile API Abuse

mobile security · low

Run

abusing-dpapi-for-credential-access

red teaming · high

Run

abusing-shadow-credentials-for-privesc

red teaming · high

Run

MITRE ATT&CK Techniques

TA0001 TA0043 TA0002

Investigate the attack patterns behind CVE-2026-104932

Casky has 447 skills that investigate the attack patterns behind CVE-2026-104932. Run one and get CVSS-scored findings in 3 minutes.

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