Heap-based buffer overflow in the Windows Internet Name Service (WINS) component for Microsoft Windows 2000 SP4 and Server 2003 SP2 allows remote attackers to execute arbitrary code via a crafted WINS replication packet that triggers an incorrect buffer-length calculation, aka "WINS Heap Overflow Vulnerability."
Conclusion & alert: CVE-2009-1923 is rated High Risk (66.4/100): CVSS Critical severity, with high exploitation likelihood (EPSS 24.66%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 37.12% | 24.66% | -12.46% |
| 2 | 2026-02-28 | 41.97% | 37.12% | -4.85% |
| 3 | 2026-01-01 | — | 41.97% | — |
Full EPSS history (29 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.3 | 2.0 | HIGH |
|
8.6 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_2000 | — | cpe:2.3:o:microsoft:windows_2000:*:sp4:*:*:*:*:*:* |
| microsoft | windows_2003_server | — | cpe:2.3:o:microsoft:windows_2003_server:-:sp2:*:*:*:*:*:* |
| microsoft | windows_2003_server | — | cpe:2.3:o:microsoft:windows_2003_server:-:sp2:itanium:*:*:*:*:* |
| microsoft | windows_2003_server | — | cpe:2.3:o:microsoft:windows_2003_server:-:sp2:x64:*:*:*:*:* |