CVE-2008-3842: Request Validation (aka the ValidateRequest filters) in ASP.NET in Microsoft .NET Framework without the MS0...

Security readout for executives and security teams

This is an old ASP.NET request validation bypass. On .NET Framework systems missing the MS07-040 update, ASP.NET may fail to block dangerous input, allowing cross-site scripting. Business impact depends on whether legacy ASP.NET applications still rely on ValidateRequest as their main input defense. Exposure is most plausible in legacy ASP.NET applications running .NET Framework installations missing MS07-040 and relying on built-in request validation instead of contextual output encoding and input handling. Prioritize if the organization still operates legacy ASP.NET applications. For modern, fully patched environments, urgency is lower, but the issue is a useful signal to review aging web platforms and XSS controls. Mitigation focus: Verify affected ASP.NET hosts have the MS07-040 update applied.; Check vendor guidance for unsupported .NET Framework deployments.; Do not rely solely on ValidateRequest for XSS prevention..

Prepared

Jun 28, 2026, 18:33 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.