How severe is CVE-2026-1773?

CVE-2026-1773 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-1773 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-1773?

CVE-2026-1773 primarily affects Hitachienergy Rtu540 Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-1773?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-1773 have an EU (EUVD) identifier?

Yes. CVE-2026-1773 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8462.

When was CVE-2026-1773 published?

CVE-2026-1773 was published on 2026-02-24 and last updated on 2026-06-17.

CVE-2026-1773

CVE-2026-1773 is a high-severity vulnerability in Hitachienergy Rtu540 Firmware with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-184.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 8.7
EPSS exploit prediction: 0% (33rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8462
Weakness: CWE-184
Affected product: Hitachienergy Rtu540 Firmware
Published: 2026-02-24
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2026-1773?: 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.
How severe is CVE-2026-1773?: CVE-2026-1773 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-1773 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (33rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-1773?: CVE-2026-1773 primarily affects Hitachienergy Rtu540 Firmware. In total, 8 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-1773?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-1773 have an EU (EUVD) identifier?: Yes. CVE-2026-1773 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8462.
When was CVE-2026-1773 published?: CVE-2026-1773 was published on 2026-02-24 and last updated on 2026-06-17.

References

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

Affected products (8)

cpe:2.3:o:hitachienergy:rtu540_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu540_firmware:13.8.1:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu560_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu560_firmware:13.8.1:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu520_firmware:13.8.1:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:*:*:*:*:*:*:*:*
cpe:2.3:o:hitachienergy:rtu530_firmware:13.8.1:*:*:*:*:*:*:*

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