Cookie handling for hosts/domains with the underscore (_) character - by Christopher Eberle

Status : 

  External<br /><br />
		This item may be valid but belongs to an external system out of the direct control of this product team.<br /><br />
		A more detailed explanation for the resolution of this particular item may have been provided in the comments section.

ID 804339 Comments
Status Closed Workarounds
Type Bug Repros 1
Opened 10/2/2013 10:58:58 AM
Access Restriction Public


Navigating to a site where the URL contains an underscore in the host portion causes internet explorer to silently fail to store cookies for that site.
This appears to be a hold-over which only affects IE (Both Google Chrome and Mozilla Firefox handle cookies for URLs with underscores in the host portion) from 2001 bulletin MS01-055.

While the impact of this is relatively small, from a business standpoint (aside from the need to rename and possibly rebuild affected servers), this "feature" breaks convention with other microsoft technologies (IIS, AD and DNS don't complain, System control panel warns when setting a name with an underscore, but it works fine otherwise). Of all the fathomable technologies, it seems that only IE has a problem with this.
Sign in to post a comment.
Posted by Microsoft on 4/4/2016 at 9:41 AM
We've moved! This issue is now being tracked at