I'm trying to set up Wordpress on a server that requires a proxy connection to connect to the internet. Here's what I put in wp-config.php:

/* Configure HTTP Proxy Server */
define('WP_PROXY_HOST', 'xx.xx.xx.xx');
define('WP_PROXY_PORT', '8080');
define('WP_PROXY_USERNAME', 'xxxxx');
define('WP_PROXY_PASSWORD', 'xxxxx');
define('WP_PROXY_BYPASS_HOSTS', 'localhost');

(I replaced real IP, username and password with xxx here for privacy reasons)

Unfortunately, Wordpress still can't connect to the internet. The Site Health page displays this error:

Your site is unable to reach WordPress.org at, and returned the error: cURL error 56: Received HTTP code 407 from proxy after CONNECT

407 is a Proxy Authentication Required error.

I checked the proxy's IP, username and password many times, and it's definitely correct. The same settings work when I use

export http_proxy="http://xxxxx:[email protected]:8080"

in the command line, and then download something using wget. It connects via proxy, and downloads the file correctly.

I tried using a packet capture program to see what the connection between Wordpress and the proxy looks like, and the headers look like this:

CONNECT api.wordpress.org:443 HTTP/1.1
Host: api.wordpress.org:443
User-Agent: WordPress/5.2.4; http://xx.xx.xx.xx/
Proxy-Connection: Keep-Alive
Connection: close

The reply from the proxy server is this:

HTTP/1.1 407 authenticationrequired
Date: Fri, 18 Oct 2019 11:31:00 GMT
Content-Type: text/html
Cache-Control: no-cache
Content-Length: 4365
Proxy-Connection: Keep-Alive
Proxy-Authenticate: Negotiate
Proxy-Authenticate: NTLM
Proxy-Authenticate: Basic realm="McAfee Web Gateway"

I think that there should have been a

Proxy-Authorization: Basic xxxxxxxxxxxxxxx

header in the first packet, but for some reason there isn't anything like it. What should I do? Am I missing something obvious here?


2 Answers 2


Not sure if this helps, but you can try..

So WordPress' default HTTP transport is using cURL, and the HTTP class sets the proxy authorization method to CURLAUTH_ANY (see source), which might explain why the Proxy-Authorization: Basic xxxxx... header is missing from the request.

And there's a hook you can try to change the proxy authorization method to CURLAUTH_BASIC (which is widely supported, but also very insecure), CURLAUTH_NTLM or one of the other available methods.

So add this to your theme functions.php file.. (or put the code into a Must-Use plugin):

add_action( 'http_api_curl', function ( $handle, $r, $url ) {
    $proxy = new WP_HTTP_Proxy();
    if ( $proxy->is_enabled() && $proxy->send_through_proxy( $url ) ) {
        curl_setopt( $handle, CURLOPT_PROXYAUTH, CURLAUTH_BASIC );
}, 10, 3 );

Alternatively, you can set PHP Streams as the default HTTP transport...

add_filter( 'http_api_transports', function ( $transports ) {
    return [ 'streams', 'curl' ];
} );

See the hook's reference and WP_Http_Streams for more information. But basically, the hook allows you to use a custom class, and WP_Http_Streams would always set the Proxy-Authorization: Basic xxxxx... header when necessary.

  • Thank you! This helped :)
    – Meeep
    Oct 22, 2019 at 13:18
  • I'm glad it helped :)
    – Sally CJ
    Oct 23, 2019 at 6:36

None of the solutions were working for me. I ended up setting the environment variable that is respected by curl in the terminal, but it only worked directly in the PHP code;



Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.