{"id":"CVE-2026-8066","title":"A directory traversal vulnerability in the file upload functionality of Hitachi Energy RTU500 allows an unauthenticated attacker to write or overwrite arbitrary files on the device file system","summary":"A directory traversal vulnerability in the file upload functionality of Hitachi Energy RTU500 allows an unauthenticated attacker to write or overwrite arbitrary files on the device file system. Depending on the files affected, successful…","severity":"critical","cvss":9.1,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","cwe":["CWE-23"],"vendor":"Hitachi Energy","product":"RTU500 series CMU firmware","affected":["rtu500_series_cmu_firmware >= 9.0 < 12.0"],"published":"2026-09-29","updated":"2026-09-29","sourceUpdated":"2026-09-29T10:17:13.250","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-8066","references":[{"url":"https://publisher.hitachienergy.com/preview?DocumentID=8DBD000251&LanguageCode=en&DocumentPartId=&Action=Launch","label":"cybersecurity@hitachienergy.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-29T09:30:49.083Z","slug":"CVE-2026-8066","body":"## Overview\n\nA directory traversal vulnerability in the file upload functionality of Hitachi Energy RTU500 allows an unauthenticated attacker to write or overwrite arbitrary files on the device file system. Depending on the files affected, successful exploitation could result in unauthorized modification of device data or disruption of the device’s intended operation.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":50,"depthScoreParts":{"impact":50.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}