WordPress Plugin Stored XSS via Search Parameter Injection

The OMGF | GDPR/DSGVO Compliant, Faster Google Fonts. Easy. plugin for WordPress is vulnerable to Stored Cross-Site Scripting via 's' Search Parameter via comments-atom Feed in all versions up to, and including, 6.3.10 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. Successful exploitation requires that the front-end server serves the retained .tmp file without a Content-Type or X-Content-Type-Options header, enabling MIME-sniffing browsers such as Chromium to execute the injected script — a condition present by default on many Apache and nginx/php-fpm deployments.

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 OMGF | GDPR/DSGVO Compliant, Faster Google Fonts plugin for WordPress contains a Stored Cross-Site Scripting (CWE-79) vulnerability in versions up to 6.3.10. The vulnerability exists in the comments-atom feed handler where the 's' search parameter is insufficiently sanitized and not properly escaped in output. This allows unauthenticated attackers to inject malicious JavaScript that persists in the database and executes whenever any user accesses the affected page. WordPress sites running this plugin are at risk, particularly those accepting public comments or feed access, as the payload becomes part of stored content accessible to all visitors.

Casky's 323 mapped security skills detect this attack pattern by identifying the MITRE ATT&CK techniques at play: TA0001 (Initial Access) where attackers inject payloads through public-facing inputs, and TA0043 (Reconnaissance) patterns that probe for unescaped output contexts. Using Claude AI with extended reasoning, practitioners would observe findings highlighting insufficient input validation in the search parameter processing, missing output encoding in feed generation, and the persistence mechanism via WordPress database storage. The skills correlate suspicious comment data flows, identify comment-atom feed handlers processing untrusted input, flag missing sanitization functions like sanitize_text_field() or wp_kses_post(), and detect absence of wp_nonce verification. Detection would surface the specific attack chain: malicious 's' parameter → database storage → rendered HTML feed → victim browser execution.

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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-2026-89417.

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-2026-89417

Casky has 323 skills that investigate the attack patterns behind CVE-2026-89417. Run one and get CVSS-scored findings in 3 minutes.

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