WordPress Create Block Plugin PHP Code Injection Flaw

The Create Block WordPress plugin before 2.10.0 does not correctly escape user-supplied text before writing it into a generated PHP pattern file, allowing a multisite subsite administrator (who holds the capability gating this action but is denied the capability that normally gates PHP file editing) to inject and execute arbitrary PHP code on the server.

Casky was already ahead

This CVE exploits attack patterns that Casky's 322matched 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

The Create Block WordPress plugin before version 2.10.0 contains a critical code injection vulnerability (CWE-94: Improper Control of Generation of Code) that allows multisite subsite administrators to execute arbitrary PHP code on affected servers. The flaw stems from insufficient input sanitization when user-supplied text is written into dynamically generated PHP pattern files. This is particularly dangerous because it affects administrators with limited permissions—those who can create blocks but lack direct PHP file editing capabilities—effectively bypassing security controls designed to restrict code execution. Any WordPress multisite installation running the vulnerable plugin version is at risk, with the attack surface extending to any subsite administrator account, making this a privilege escalation and code execution threat.

Casky's 322 mapped security skills leverage Claude AI's extended reasoning to detect this attack pattern by analyzing behaviors associated with MITRE ATT&CK techniques TA0001 (Initial Access) and TA0043 (Reconnaissance). Practitioners using Casky would identify suspicious activity patterns including: unusual file write operations to PHP pattern directories from administrative functions, unexpected PHP syntax appearing in user input parameters passed to the Create Block plugin, and post-exploitation indicators showing PHP code execution in contexts where only text input should exist. The platform's skills would correlate these signals to flag the injection vector, helping teams recognize when an attacker is attempting to abuse the plugin's text escaping weakness to transition from limited administrative access into unrestricted code execution on the web server.

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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 →

322 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-16623.

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

Investigate the attack patterns behind CVE-2026-16623

Casky has 322 skills that investigate the attack patterns behind CVE-2026-16623. Run one and get CVSS-scored findings in 3 minutes.

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