The Web Proxy Auto-Discovery (WPAD) functionality in Microsoft .NET Framework 2.0 SP2, 3.5, 3.5.1, 4, and 4.5 does not validate configuration data that is returned during acquisition of proxy settings, which allows remote attackers to execute arbitrary JavaScript code by providing crafted data during execution of (1) an XAML browser application (aka XBAP) or (2) a .NET Framework application, aka "Web Proxy Auto-Discovery Vulnerability."
Conclusion & alert: CVE-2012-4776 is rated High Risk (67.7/100): CVSS Critical severity, with high exploitation likelihood (EPSS 45.02%, 97th 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 | 2026-01-27 | 48.63% | 45.02% | -3.61% |
| 2 | 2025-12-28 | 48.83% | 48.63% | -0.20% |
| 3 | 2025-12-27 | — | 48.83% | — |
Full EPSS history (19 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 | .net_framework | 2.0 | cpe:2.3:a:microsoft:.net_framework:2.0:sp2:*:*:*:*:*:* |
| microsoft | .net_framework | 3.5.1 | cpe:2.3:a:microsoft:.net_framework:3.5.1:*:*:*:*:*:*:* |
| microsoft | .net_framework | 4.0 | cpe:2.3:a:microsoft:.net_framework:4.0:*:*:*:*:*:*:* |
| microsoft | .net_framework | 3.5 | cpe:2.3:a:microsoft:.net_framework:3.5:*:*:*:*:*:*:* |
| microsoft | .net_framework | 4.5 | cpe:2.3:a:microsoft:.net_framework:4.5:*:*:*:*:*:*:* |