PatchSiren cyber security CVE debrief
CVE-2026-28704 Japan Computer Emergency Response Team Coordination Center (JPCERT/CC) CVE debrief
CVE-2026-28704 is a high-severity vulnerability in JPCERT's EmoCheck, a tool designed to detect and analyze malware. The vulnerability exists due to insecure loading of Dynamic Link Libraries (DLLs). An attacker can exploit this vulnerability by placing a crafted DLL file in the same directory as EmoCheck, allowing arbitrary code execution with the privileges of the user invoking EmoCheck. The vulnerability has a CVSS score of 8.4 and is classified as HIGH severity.
- Vendor
- Japan Computer Emergency Response Team Coordination Center (JPCERT/CC)
- Product
- Emocheck
- CVSS
- HIGH 8.4
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-04-10
- Original CVE updated
- 2026-06-08
- Advisory published
- 2026-04-10
- Advisory updated
- 2026-06-08
Who should care
Users of EmoCheck, particularly those in environments where the tool is used to detect and analyze malware, should be aware of this vulnerability and take steps to mitigate it.
Technical summary
The vulnerability is caused by EmoCheck's insecure DLL loading mechanism. When EmoCheck is executed, it loads DLLs from the same directory. An attacker can exploit this by creating a crafted DLL with the same name as a legitimate DLL required by EmoCheck, allowing arbitrary code execution when EmoCheck is run.
Defensive priority
High
Recommended defensive actions
- Update EmoCheck to the latest version, if available.
- Ensure that the directory containing EmoCheck is restricted to authorized users only.
- Use secure coding practices when developing and loading DLLs.
- Monitor the directory containing EmoCheck for suspicious activity.
Evidence notes
The vulnerability was reported by JPCERT and is tracked as CVE-2026-28704. The CVSS score is 8.4, indicating high severity.
Sources and references
Verified primary and authoritative sources
-
CVE-2026-28704 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-28704
CVE Program - Official CVE Program record with source-provided CVE metadata.
-
CVE-2026-28704 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-28704
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
-
Source reference
Unverified legacy reference
URL: https://github.com/JPCERTCC/EmoCheck/
[email protected] - Product
-
Mitigation or vendor reference
Unverified legacy reference
URL: https://jvn.jp/en/jp/JVN00263243/
[email protected] - Third Party Advisory
-
Mitigation or vendor reference
Unverified legacy reference
URL: https://www.jpcert.or.jp/press/2026/PR20260410.html
[email protected] - Third Party Advisory
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.