CVE-2026-1773

State: Published
Severity: 8.7 High
Published: Feb 24, 2026
Updated: May 27, 2026
Reserved: Feb 2, 2026

Description

IEC 60870-5-104 used in RTU500: Potential Denial of Service impact on reception of invalid U-format frame. Product is only affected if IEC 60870-5-104 bi-directional functionality is configured. Enabling secure communication following IEC 62351-3 does not remediate the vulnerability but mitigates the risk of exploitation.

Scores

CVSS	Score	Vector	Source
4.0	8.7 High	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N	Hitachi Energy

Weaknesses

CWE-184 Incomplete List of Disallowed Inputs

Affected Products

Product	Versions
RTU500 series CMU firmwareHitachi Energy	12.7.1 through 12.7.7Affected 13.5.1 through 13.5.4Affected 13.6.1 through 13.6.2Affected 13.7.1 through 13.7.7Affected 13.8.1Affected

References

https://publisher.hitachienergy.com/preview?DocumentID=8DBD000237&LanguageCode=en&DocumentPartId=&Action=Launch

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