IEC 60870-5-104: 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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact None

Vulnerable System Availability Impact High

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Hitachi Energy RTU500 series CMU firmware unaffected
Version Status Constraints
12.7.1 affected ≤ 12.7.7
13.5.1 affected ≤ 13.5.4
13.6.1 affected ≤ 13.6.2
13.7.1 affected ≤ 13.7.7
13.8.1 affected —

No data.

No data.

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Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://publisher.hitachienergy.com/preview?DocumentID=8DBD000237&LanguageCode=en&DocumentPartId=&Action=Launch cve-icon cve-icon
History

Tue, 24 Feb 2026 14:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-20 CWE-184

Tue, 24 Feb 2026 13:30:00 +0000

Type Values Removed Values Added
Description IEC 60870-5-104: 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.
Weaknesses CWE-20
References
Metrics cvssV4_0

{'score': 8.7, 'vector': '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'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Hitachi Energy

Published:

Updated: 2026-02-24T13:40:55.104Z

Reserved: 2026-02-02T16:28:59.394Z

Link: CVE-2026-1773

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-24T14:16:22.420

Modified: 2026-02-24T14:16:22.420

Link: CVE-2026-1773

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses