CVE-2026-8066CWE-23

CVE-2026-8066

Critical · published September 29, 2026

CVSS v3.1
9.1
EPSS
1%
Percentile
54.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
9.1 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00736 · 54.0th percentile
Weakness
CWE-23 · Relative Path Traversal
Published
2026-09-29T14:17Z
References (1)
https://publisher.hitachienergy.com/preview?DocumentID=8DBD000251&LanguageCode=en&DocumentPartId=&Action=Launch · [email protected]
EPSS history
Timeline
  • 30 SEP 03:29Z
    EPSS moved — → 1%
    epss
  • 29 SEP 09:24Z
    A directory traversal vulnerability in the file upload functionality of Hitachi Energy RTU500 allows an unauthenticated attacker to write or overwrite…
    cvelistv5