CVE-2026-8065

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.

  • Published Sep 29, 2026
  • CVSS 9.1 critical
  • 0.6% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-8065 at the National Vulnerability Database