- Critical 9.1
CVE-2026-8066
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.
Scores
The facts
- Published
- 29 September 2026
- Last changed
- 29 September 2026
- NVD status
- Awaiting Analysis
- Severity
- Critical, CVSS 9.1 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H - Weakness
- Known exploited
- Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
- EPSS
- 0.7% chance of exploitation activity in the next 30 days (percentile 54).
Is there a Securelyn advisory?
Not yet. Securelyn writes plain-English advisories for the flaws that matter most to businesses. Subscribe to the digest to hear about them.