NULL Pointer Dereference Vulnerability in RTU500 from Hitachi Energy
CVE-2026-17539

5.9MEDIUM

Key Information:

Vendor

Hitachi
Status
Rtu500 Series Cmu Firmware
Vendor
CVE Published:
3 September 2026

What is CVE-2026-17539?

The RTU500 device manufactured by Hitachi Energy is susceptible to a NULL pointer dereference vulnerability under high-load conditions. Specifically, when GI requests are sent at short intervals, the enhanced message queue can experience a critical failure. This leads to a BCI_IEC104 fatal write error, which interrupts the connection and potentially restarts the system, resulting in a denial of service for bidirectional IEC 60870-5-104 communication, impacting operational continuity.

Affected Version(s)

RTU500 series CMU firmware 12.7.1 <= 12.7.7

RTU500 series CMU firmware 13.5.1 <= 13.5.4

RTU500 series CMU firmware 13.6.1 <= 13.6.3

References

https://publisher.hitachienergy.com/preview?DocumentID=8D...

CVSS V3.1

Score:
5.9
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.