WordPress YOP Poll Plugin Origin Validation Flaw

The YOP Poll plugin for WordPress is vulnerable to Origin Validation Error in all versions up to, and including, 7.0.10. This is due to the plugin transmitting a wp_rest nonce to window.opener via postMessage() with a wildcard targetOrigin. This makes it possible for unauthenticated attackers to steal a REST nonce scoped to a logged-in Administrator and use it to change the Administrator's email address and password, resulting in full account takeover. The Administrator must open an attacker-controlled page in order to exploit this vulnerability.

Casky was already ahead

This CVE exploits attack patterns that Casky's 323matched 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 YOP Poll plugin for WordPress contains a critical origin validation error (CWE-346) that allows attackers to intercept sensitive REST API nonces through insecure cross-origin messaging. By exploiting the plugin's use of postMessage() with a wildcard targetOrigin, unauthenticated threat actors can steal nonces scoped to logged-in administrators. This stolen credential can then be weaponized to change administrator email addresses and passwords, leading to complete account takeover. Any WordPress installation running YOP Poll versions 7.0.10 and earlier is vulnerable, regardless of other security controls, making this a high-severity risk affecting site administrators and their organizations.

Casky's 323 matched security skills leverage Claude's extended reasoning to detect the attack patterns underlying this vulnerability across MITRE techniques TA0001 (Reconnaissance) and TA0043 (Reconnaissance). Practitioners using Casky would identify suspicious postMessage() calls with overly permissive origin specifications, detect unusual REST nonce transmission patterns to window.opener, and flag cross-origin authentication token exposure. The platform's skills would surface indicators such as unauthorized nonce generation, unexpected administrator credential modifications, and anomalous email change requests originating from external origins—enabling security teams to catch exploitation attempts before account compromise occurs.

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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 →

323 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2026-85682.

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-2026-85682

Casky has 323 skills that investigate the attack patterns behind CVE-2026-85682. Run one and get CVSS-scored findings in 3 minutes.

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