CVE-2026-9853

HIGH 8.5 ALL-YEARS

Published 2026-09-03 · Last modified 2026-09-03 · Hitachi Energy · NVD: Analyzed

A vulnerability exists in SYS600 which allows any user authenticated to the operating system of the server hosting the application to read and modify application objects without being authenticated to the SYS600 system itself. Only the SYS600 system users should be permitted to view and modify application objects.

ELEVATED IMPACT

Severe if exploited (CVSS 8.5), but no confirmed exploitation. Patch on a normal cadence.

Exploitation likelihood

0.1%chance of exploitation in 30 days · 4th percentile

○ In CISA KEV○ Catalogued PoC◆ SSVC: exploitation none, automatable no

Impact if exploited

8.5CVSS 4.0 · HIGH · CNA

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

What an attacker needs

⚠Access: Requires local access to the host
⚠Privileges: Requires a low-privilege account
✓User interaction: No user interaction needed
✓Complexity: No special conditions — reliably repeatable
✓Requirements: No special attack requirements

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

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Affected

Vendors Hitachi Energy Hitachienergy

Products Microscada Sys600 Microscada X Sys600

Weakness (CWE)

CWE-303: Incorrect implementation of authentication algorithm

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References and research data (JSON)

Known Affected Software Configurations

Vendor	Product	Version range
Hitachienergy	Microscada X Sys600	≥ 10.0 and ≤ 10.8

All CVSS metrics

HIGH 8.5 v4.0 · CNA Primary
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
HIGH 8.5 v4.0 · NVD Secondary
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
HIGH 7.8 v3.1 · NVD Primary
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Advisories

https://publisher.hitachienergy.com/preview?DocumentID=8DBD000249&LanguageCode=en&DocumentPartId=&Action=Launch Vendor AdvisoryCVE record · Hitachi Energy · Updated 2026-09-03T07:53:35.276Z
NVD · CVE-2026-9853 · Updated 2026-09-09T19:36:31.563
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-70320 ADVISORYEUVD · EUVD-2026-70320

Sources: NVD · CVE.org · All sources and attribution · EPSS