CVE-2026-8066

critical

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.

References

https://www.cisa.gov/news-events/ics-advisories/icsa-26-279-06

https://publisher.hitachienergy.com/preview?DocumentID=8DBD000251&LanguageCode=en&DocumentPartId=&Action=Launch

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-88669

Details

Source: Mitre, NVD

Published: 2026-09-29

Updated: 2026-09-29

Risk Information

CVSS v2

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:C

Severity: High

CVSS v3

Base Score: 9.1

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Severity: Critical

EPSS

EPSS: 0.00736