{"schemaVersion":3,"id":"CVE-2026-8066","aliases":[],"status":"published","duplicateOf":null,"title":null,"description":"A directory traversal vulnerability in the file upload functionality of Hitachi Energy RTU500 end-of-life versions 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.","dates":{"published":"2026-09-29T09:24:05.830Z","modified":"2026-09-29T15:52:33.807Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":9.1,"severity":"critical","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"NVD","score":9.1,"severity":"critical","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H","exploitability":null,"impact":null,"computed":false}]},"epss":{"probability":0.00736,"percentile":0.53903,"severity":"low","asOf":"2026-10-21T00:00:00.000Z","change":{"pp":null,"baselineDate":null,"baselineScore":null},"history":[{"date":"2026-09-29T00:00:00.000Z","score":0.01157,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00736,"percentile":0.53903}],"last30":[{"date":"2026-09-29T00:00:00.000Z","score":0.01157,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-20T00:00:00.000Z","score":0.00736,"percentile":null},{"date":"2026-10-21T00:00:00.000Z","score":0.00736,"percentile":0.53903}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-23","name":"Relative Path Traversal","description":"The product uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize sequences such as \"..\" that can resolve to a location that is outside of that directory.","type":"weakness","status":"Draft","abstraction":"Base","likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/23.html"}],"affected":[{"vendor":"hitachi energy","product":"rtu500 series cmu firmware","name":"RTU500 series CMU Firmware","label":"rtu500 series cmu firmware","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 9.0, < 12.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 9.0, < 12.0","eol":null,"hubHref":"/vendor/hitachi_energy/rtu500_series_cmu_firmware"}],"affectedCount":1,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://publisher.hitachienergy.com/preview?DocumentID=8DBD000251&LanguageCode=en&DocumentPartId=&Action=Launch","label":"publisher.hitachienergy.com/preview","hostname":"publisher.hitachienergy.com","tags":[]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2026-09-29T09:24:05.830Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2026-09-29T15:52:33.807Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":70,"level":"high","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-22T01:59:51.282Z","stale":false,"partial":false}}