CVE-2026-8479

mediumpriority · track · 0EPSS 0.002 · 15 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.25% (15th) EPSS

CVSS 6.5 · medium

Is it mine?

15 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · cisa_csaf_ot

EPSS · scored 2026-10-22

IEC 60870-5-104 used in bidirectional mode in RTU500 is vulnerable for a NULL pointer dereferencing, if a specially crafted sequence of messages is sent for a certain time, causing Denial of Service impact. Product is only affected if IEC 60870-5-104 functionality in bidirectional mode (BCI) is configured.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedRTU500 series CMU Firmwarecisa_csaf_ot
Update to CMU Firmware version 13.7.8
MitigationRTU500 series CMU Firmwarecisa_csaf_ot
Follow general mitigation factors/workarounds

cvss

Technical severity, 0–10. One row per scoring source.

6.9

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.16.5mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hsecondary · CISA US

v4.06.9mediumCVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:Nsecondary · ENISA EU

v4.06.9mediumCVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/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:Xsecondary · cybersecurity@hitachienergy.com

v4.04.6mediumCVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/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:Xsecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-476USCWE-476US

affected products (15)

Products and version ranges known to be affected.

RTU500 series CMU Firmware version 12.7.1 – 12.7.7all versionscisa_csaf_otUS
RTU500 series CMU Firmware version 13.5.1 – 13.5.4all versionscisa_csaf_otUS
RTU500 series CMU Firmware version 13.6.1 – 13.6.3all versionscisa_csaf_otUS
RTU500 series CMU Firmware version 13.7.1 – 13.7.7all versionscisa_csaf_otUS
RTU500 series CMU Firmware version 13.8.1all versionscisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=13.5.1|<=13.5.4cisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmwareall versionscisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=12.7.1|<=12.7.7cisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=13.6.1|<=13.6.3cisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ vers:RTU500_series_CMU_Firmware/>=13.7.1|<=13.7.7cisa_csaf_otUS
Hitachi Energy RTU500 series CMU Firmware≤ 13.8.1enisa_euvdEU
Hitachi Energy RTU500 series CMU Firmware≤ 13.6.1 ≤13.6.3enisa_euvdEU
Hitachi Energy RTU500 series CMU Firmware≤ 13.5.1 ≤13.5.4enisa_euvdEU
Hitachi Energy RTU500 series CMU Firmware≤ 13.7.1 ≤13.7.8enisa_euvdEU
Hitachi Energy RTU500 series CMU Firmware≤ 12.7.1 ≤12.7.7enisa_euvdEU

advisories (1)

Vendor and ecosystem advisories describing this.

ICSA-26-155-04Hitachi Energy RTU5002026-05-26icsa · cisa_csaf_otUS
Hitachi Energy is aware of vulnerabilities that affect RTU500 product versions listed in this document. If exploited, these vulnerabilities primarily impact product availability, with potential secondary impacts on confidentiality and integrity. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cisa_csaf_ot NVD CVE.org MITRE

published 2026-05-26modified 2026-07-23

references (3)

External citations — patches, advisories, analysis.

scry

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