CVE-2026-42945
View CSAF Summary Hitachi Energy is aware of a buffer overflow vulnerability that affects e-mesh EMS product versions listed in this document. Successful exploitation of this vulnerability could lead to a buffer overflow condition, potentially resulting in application outages (denial of service) and possible arbitrary code execution. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation. The following versions of Hitachi Energy e-mesh EMS are affected: Hitachi Energy e-mesh EMS 4.1.6, 4.4.2, 4.7.0 CVSS Vendor Equipment Vulnerabilities v3 8.1 Hitachi Energy Hitachi Energy e-mesh EMS Heap-based Buffer Overflow Background Critical Infrastructure Sectors: Energy Countries/Areas Deployed: Worldwide Company Headquarters Location: Switzerland Vulnerabilities Expand All + CVE-2026-42945 NGINX Plus and NGINX Open Source used in e-mesh EMS have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. e-mesh EMS versions using NGINX v1.30.0 and below are affected. View CVE Details Affected Products Hitachi Energy e-mesh EMS Vendor: Hitachi Energy Product Version: e-mesh EMS versions 4.1.6, e-mesh EMS versions 4.4.2, e-mesh EMS versions 4.7.0 Product Status: known_affected Remediations Vendor fix Apply hotfix for respective e-mesh EMS versions to update NGINX to either v1.30.2 or latest Mitigation Ensure rewrite configuration does
CSIRTS triage
- What
- A buffer overflow vulnerability could lead to application outages and arbitrary code execution.
- Who is affected
- Deployments of e-mesh EMS versions 4.1.6, 4.4.2, and 4.7.0 worldwide.
- Urgency
- Remediation is critical due to the high CVSS score and potential for severe impact.
- Action
- Apply the recommended immediate actions for mitigation or remediation.
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Exploitation outlook
- Exploitation likely imminentEPSS puts this in the most-targeted tier (61.5% 30-day exploitation probability). Prioritize alongside KEV items. Riskier than 99% of all EPSS-scored CVEs.
Advisory coverage (2)
- high[UPDATE] [high] NGINX Open Source and NGINX Plus: Multiple vulnerabilitiescert-bund · 2026-07-10
- criticalHitachi Energy e-mesh EMScisa · 2026-07-07
External references
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