CVE-2026-8479: CWE-476 NULL pointer dereference in Hitachi Energy RTU500 series CMU firmware
CVE-2026-8479 is a medium severity vulnerability in Hitachi Energy RTU500 series CMU firmware. It involves a NULL pointer dereference in the IEC 60870-5-104 protocol when used in bidirectional mode (BCI). This can be triggered by sending a specially crafted sequence of messages over time, resulting in a denial of service (DoS) condition. The vulnerability only affects devices with the IEC 60870-5-104 bidirectional mode configured. There is no official patch or remediation level provided by the vendor at this time, and no known exploits have been reported in the wild.
AI Analysis
Technical Summary
The Hitachi Energy RTU500 series CMU firmware contains a vulnerability identified as CVE-2026-8479, classified under CWE-476 (NULL pointer dereference). This occurs in the IEC 60870-5-104 protocol implementation when operating in bidirectional mode (BCI). An attacker capable of sending a specific sequence of crafted messages over a period can cause the firmware to dereference a NULL pointer, leading to a denial of service. The affected firmware versions include 12.7.1, 13.5.1, 13.6.1, 13.7.1, and 13.8.1. The CVSS v4.0 base score is 6.9, indicating medium severity, with attack vector as adjacent network, low attack complexity, and requiring low privileges but no user interaction.
Potential Impact
Successful exploitation results in a denial of service condition on affected RTU500 series devices configured with IEC 60870-5-104 bidirectional mode. This could disrupt communication or control functions relying on the protocol, potentially impacting operational availability. There are no reports of code execution or data compromise associated with this vulnerability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no official fix or remediation level is provided by Hitachi Energy, users should monitor vendor communications for updates. Until a patch is available, consider disabling IEC 60870-5-104 bidirectional mode if it is not required, to mitigate exposure to this vulnerability.
CVE-2026-8479: CWE-476 NULL pointer dereference in Hitachi Energy RTU500 series CMU firmware
Description
CVE-2026-8479 is a medium severity vulnerability in Hitachi Energy RTU500 series CMU firmware. It involves a NULL pointer dereference in the IEC 60870-5-104 protocol when used in bidirectional mode (BCI). This can be triggered by sending a specially crafted sequence of messages over time, resulting in a denial of service (DoS) condition. The vulnerability only affects devices with the IEC 60870-5-104 bidirectional mode configured. There is no official patch or remediation level provided by the vendor at this time, and no known exploits have been reported in the wild.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Hitachi Energy RTU500 series CMU firmware contains a vulnerability identified as CVE-2026-8479, classified under CWE-476 (NULL pointer dereference). This occurs in the IEC 60870-5-104 protocol implementation when operating in bidirectional mode (BCI). An attacker capable of sending a specific sequence of crafted messages over a period can cause the firmware to dereference a NULL pointer, leading to a denial of service. The affected firmware versions include 12.7.1, 13.5.1, 13.6.1, 13.7.1, and 13.8.1. The CVSS v4.0 base score is 6.9, indicating medium severity, with attack vector as adjacent network, low attack complexity, and requiring low privileges but no user interaction.
Potential Impact
Successful exploitation results in a denial of service condition on affected RTU500 series devices configured with IEC 60870-5-104 bidirectional mode. This could disrupt communication or control functions relying on the protocol, potentially impacting operational availability. There are no reports of code execution or data compromise associated with this vulnerability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Since no official fix or remediation level is provided by Hitachi Energy, users should monitor vendor communications for updates. Until a patch is available, consider disabling IEC 60870-5-104 bidirectional mode if it is not required, to mitigate exposure to this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Hitachi Energy
- Date Reserved
- 2026-05-13T13:42:53.588Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a15a0f6891d628fdc365f00
Added to database: 5/26/2026, 1:32:38 PM
Last enriched: 5/26/2026, 1:48:16 PM
Last updated: 5/26/2026, 3:07:17 PM
Views: 3
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