---
id: CVE-2026-8065
title: >-
  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
summary: >-
  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 …
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-306
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: '2026-09-29T21:39:02.570'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-8065'
references:
  - url: >-
      https://publisher.hitachienergy.com/preview?DocumentID=8DBD000251&LanguageCode=en&DocumentPartId=&Action=Launch
    label: cybersecurity@hitachienergy.com
tags:
  - nvd
  - exploit-available
  - cve.org
epss: 0.00494
epssPercentile: 0.42238
exploits:
  github: 2
  githubRepos:
    - 'https://github.com/MRdark-ops/CVE-2026-8065'
    - 'https://github.com/murrez/CVE-2026-8065'
  checkedAt: '2026-10-27T19:14:51.015Z'
exploitAvailable: true
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-29T15:53:38.135052Z'
ingestedAt: '2026-09-29T09:30:49.084Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.