{"id":"CVE-2026-71920","title":"Multiple DrayTek VigorSwitch models contain a null pointer dereference vulnerability in the formlogout function","summary":"Multiple DrayTek VigorSwitch models contain a null pointer dereference vulnerability in the formlogout function. The vulnerability is caused by missing checks for an empty or absent Cookie header before string handling. A remote attacker…","severity":"medium","cvss":4.9,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"published":"2026-08-24","updated":"2026-10-13","sourceUpdated":"2026-10-13T09:10:00.323","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-71920","references":[{"url":"https://www.draytek.com/about/security-advisory/multiple-vulnerabilities-in-vigorswitch-series-august-2026/","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/draytek-vigorswitch-multiple-models-null-pointer-dereference-via-formlogout","label":"disclosure@vulncheck.com"}],"tags":["nvd"],"epss":0.00556,"epssPercentile":0.44802,"ingestedAt":"2026-10-13T09:20:23.182Z","slug":"CVE-2026-71920","body":"## Overview\n\nMultiple DrayTek VigorSwitch models contain a null pointer dereference vulnerability in the formlogout function. The vulnerability is caused by missing checks for an empty or absent Cookie header before string handling. A remote attacker can trigger this vulnerability via a crafted request to crash the service and cause a denial of service. Exploitation requires valid administrative credentials for the device's web management interface.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":27,"depthScoreParts":{"impact":27,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}