CVE-2026-8065CWE-306

CVE-2026-8065

Critical · published September 29, 2026

CVSS v3.1
9.1
EPSS
1%
Percentile
46.8
In the wild
Unconfirmed
What it is

An authentication bypass vulnerability in the firmware update endpoint of Hitachi Energy RTU500 end-of-life versions allows an unauthenticated attacker to upload arbitrary firmware through a crafted POST request. Successful exploitation could allow the attacker to modify device functionality or compromise the integrity or availability of the device.

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
0.00577 · 46.8th percentile
Weakness
CWE-306 · Missing Authentication for Critical Function
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 09:20Z
    An authentication bypass vulnerability in the firmware update endpoint of Hitachi Energy RTU500 allows an unauthenticated attacker to upload arbitrary firmware…
    cvelistv5