ASP.NET url MAX_PATH limit

asp.net url isapi max-path
Greg Ballard picture Greg Ballard · Nov 5, 2008 · Viewed 9.8k times · Source

I've found an issue with ASP.NET that I know at least has stumped one other person out there. We were trying to use an HttpModule to handle wildcard requests to a web application. The generated url is dynamic and could potentially be several hundred characters long. Unfortunately there appears to be a limitation in the aspnet_isapi.dll file that limits the length of the path in the url to MAX_PATH which is hardcoded at 260 chars.

Has anyone else ran into this and found a way around this limit? Query string parameters are not an option.

Thanks, Greg Ballard

Answer

Haacked picture Haacked · Nov 5, 2008

This is a known issue with aspnet_isapi.dll and there is currently no workaround. The reason you don't see this issue when running your site in the built-in Visual Studio Webserver (aka Cassini) is because it's all managed code and doesn't rely on aspnet_isapi.dll.

This will get addressed in a future version of ASP.NET.

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