CVE-2026-17539: CWE-476 NULL pointer dereference in Hitachi Energy RTU500 series CMU firmware
Description
RTU500 has a vulnerability, where high-load scenarios, such as sending GI requests at short intervals, may cause a NULL pointer dereference in the last entry of the enhanced message queue. This can cause a BCI_IEC104 fatal write error, resulting in connection interruption and restart, and ultimately a denial of service for bidirectional IEC 60870-5-104 communication.
CVSS v3.1
Score 5.9medium
Affected software
Hitachi Energy
RTU500 series CMU firmware
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The RTU500 series CMU firmware from Hitachi Energy contains a NULL pointer dereference vulnerability (CWE-476) triggered by high-load scenarios like sending GI requests at short intervals. This flaw causes a fatal write error in the IEC 60870-5-104 communication protocol implementation, resulting in connection interruptions and forced restarts. The vulnerability leads to denial of service conditions affecting bidirectional communication. No official patch or remediation level has been published by the vendor as of the data provided.
Potential Impact
Exploitation of this vulnerability results in denial of service by interrupting and restarting the IEC 60870-5-104 communication connection. This impacts availability of the affected RTU500 series CMU firmware devices during high-load conditions. There is no indication of confidentiality or integrity impact.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, avoid high-load scenarios such as sending GI requests at short intervals that trigger the NULL pointer dereference. Monitor vendor communications for updates on official patches or mitigations.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- Hitachi Energy
- Date Reserved
- 2026-07-27T09:46:09.631Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6a992adaacd9273b49a53d86
Added to database: 09/03/2026, 08:07:54 UTC
Last enriched: 09/07/2026, 13:14:28 UTC
Last updated: 10/18/2026, 06:48:15 UTC
Views: 104
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