WordPress Link Whisper Plugin Stored XSS via User ID Parameter

The Link Whisper Free plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the user_id parameter in all versions up to, and including, 0.9.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Casky was already ahead

This CVE exploits attack patterns that Casky's 301matched 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 Link Whisper Free plugin for WordPress contains a Stored Cross-Site Scripting (XSS) vulnerability in versions up to 0.9.0, where the user_id parameter fails to properly sanitize and escape user input. This allows unauthenticated attackers to inject malicious JavaScript code that persists in the WordPress database and executes whenever any user visits an affected page. Organizations running WordPress sites with this plugin are at risk of account compromise, credential theft, malware distribution, and unauthorized administrative actions—all without requiring users to click suspicious links or interact with obvious attack vectors.

Casky.ai's 301 matched security skills map this vulnerability across two critical MITRE ATT&CK techniques: Initial Access (TA0001) and Persistence (TA0043). Using Claude AI with extended reasoning, Casky detects the attack patterns by identifying stored payload injection points where unsanitized parameters flow directly to page output without proper escaping. Practitioners using Casky would see findings highlighting the absence of input validation on the user_id parameter, detection of script tag injection opportunities, and persistence indicators showing how injected code remains active across user sessions. The platform correlates these signals with known XSS attack chains, enabling security teams to prioritize remediation of vulnerable plugin versions and implement output encoding controls before attackers achieve sustained compromise of WordPress environments.

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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 →

301 Casky skills cover this attack pattern

These skills use Claude AI's reasoning model to surface findings in the same attack categories as CVE-2025-11262.

analyzing-apt-group-with-mitre-navigator

threat intelligence · low

Run

analyzing-campaign-attribution-evidence

threat intelligence · low

Run

analyzing-certificate-transparency-for-phishing

threat intelligence · low

Run

MITRE ATT&CK Techniques

TA0001 TA0043

Investigate the attack patterns behind CVE-2025-11262

Casky has 301 skills that investigate the attack patterns behind CVE-2025-11262. Run one and get CVSS-scored findings in 3 minutes.

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