Active Directory Federation Services (ADFS) in Microsoft Windows Server 2003 SP2 and Server 2008 Gold and SP2 does not properly validate headers in HTTP requests, which allows remote authenticated users to execute arbitrary code via a crafted request to an IIS web server, aka "Remote Code Execution in ADFS Vulnerability."
Conclusion & alert: CVE-2009-2509 is rated High Risk (67.6/100): CVSS Critical severity, with high exploitation likelihood (EPSS 26.76%, 96th 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 | 2026-04-30 | 28.93% | 26.76% | -2.17% |
| 2 | 2025-03-30 | 21.27% | 28.93% | +7.66% |
| 3 | 2025-03-29 | — | 21.27% | — |
Full EPSS history (23 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.0 | 2.0 | HIGH |
|
8.0 | 10.0 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| microsoft | windows_server_2003 | — | cpe:2.3:o:microsoft:windows_server_2003:*:sp2:*:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:*:*:x32:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:*:*:x64:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x32:*:*:*:*:* |
| microsoft | windows_server_2008 | — | cpe:2.3:o:microsoft:windows_server_2008:*:sp2:x64:*:*:*:*:* |