An issue in Hikvision DS-2CD1321-I V5.7.21 build 230819 allows attackers to cause a Denial of Service (DoS) via sending a crafted POST request to the endpoint /ISAPI/Security/challenge. The vendor has stated that upgrading to V5.7.23_SP2 fixes the issue.
Conclusion & alert: CVE-2025-45851 is rated Moderate Risk (51.7/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.40%).Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
Exploit prediction scoring system (EPSS) score for CVE-2025-45851
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).