Vulnerability · Published Feb 24, 2026 · Assigned by Hitachi Energy
CVE-2026-1773
High 8.7
In plain English
A high-severity security flaw in RTU500 series CMU firmware from Hitachi Energy. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Severity (CVSS 4.0)8.7High
Exploit odds (30 days)0.5%top 60.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
IEC 60870-5-104 used in RTU500: Potential Denial of Service impact on reception of invalid U-format frame. Product is only affected if IEC 60870-5-104 bi-directional functionality is configured. Enabling secure communication following IEC 62351-3 does not remediate the vulnerability but mitigates the risk of exploitation.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Hitachi Energy | RTU500 series CMU firmware | 12.7.1 – through 12.7.713.5.1 – through 13.5.413.6.1 – through 13.6.213.7.1 – through 13.7.713.8.1 |
Weakness: CWE-184 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N