CVE-2026-8479

Service interruption via BCI NULL pointer dereference

Published May 26, 2026 · Updated May 26, 2026

NULL pointer dereference in Hitachi Energy RTU500 CMU firmware allows attackers to interrupt the IEC 60870-5-104 service. The BCI message-processing path dereferences a NULL pointer after a specially crafted message sequence is sustained for an unspecified period. Exploitation requires adjacent-network access, low privileges, and configured IEC 60870-5-104 bidirectional mode; the published impact is loss of availability only.

CVSS severity6.9
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in Hitachi Energy RTU500 CMU firmware allows attackers to interrupt the IEC 60870-5-104 service. The BCI message-processing path dereferences a NULL pointer after a specially crafted message sequence is sustained for an unspecified period. Exploitation requires adjacent-network access, low privileges, and configured IEC 60870-5-104 bidirectional mode; the published impact is loss of availability only.

The record

CVE
CVE-2026-8479
Published
May 26, 2026
Updated
May 26, 2026
Vendor
Hitachi Energy
Product
RTU500 Series CMU Firmware
Classifications
CWE-476, T0814
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 2026CVE publishedPublication date reported by the CVE source.
  2. May 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=12.7.1 <=12.7.7
  2. Affected versionversion=13.5.1 <=13.5.4
  3. Affected versionversion=13.6.1 <=13.6.3
  4. Affected versionversion=13.7.1 <=13.7.8
  5. Affected versionversion=13.8.1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Hitachi Energy · RTU500 Series CMU Firmwareversion=12.7.1 <=12.7.7; version=13.5.1 <=13.5.4; version=13.6.1 <=13.6.3; version=13.7.1 <=13.7.8; version=13.8.1

Published CVSS scores

6.9Hitachi EnergyCVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T0814Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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