[wp-trac] [WordPress Trac] #40917: Some HTTP headers are duplicated on admin-ajax.php responses

[WordPress Trac]

#40917: Some HTTP headers are duplicated on admin-ajax.php responses
----------------------------+-----------------------------
 Reporter:  EatonZ          |      Owner:
     Type:  defect (bug)    |     Status:  new
 Priority:  normal          |  Milestone:  Awaiting Review
Component:  Administration  |    Version:  4.7.5
 Severity:  normal          |   Keywords:
  Focuses:                  |
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 When a request is sent via admin-ajax.php, the response consistently
 includes some duplicated HTTP headers.

 This is likely related to IIS, as the site is running on IIS 8.5.

 The following are the custom headers specified in my web.config file:

 {{{
 <customHeaders>
   <add name="Arr-Disable-Session-Affinity" value="true" />
   <add name="Referrer-Policy" value="no-referrer-when-downgrade" />
   <add name="X-Content-Type-Options" value="nosniff" />
   <add name="X-Frame-Options" value="SAMEORIGIN" />
   <add name="X-XSS-Protection" value="1; mode=block" />
   <remove name="X-Powered-By" />
 </customHeaders>
 }}}

 Please refer to the attached screenshot. You can see that some of the
 custom headers I have specified get duplicated.

 This looks to be a bug. Please let me know if you need anymore details.

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Ticket URL: <https://core.trac.wordpress.org/ticket/40917>
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