php 5.6.9 - the same bug
OS - Ubuntu 14.10

Can be fixed with this workaround. Need to add stream context param to SoapClient.

$client = new SoapClient("https://IP:443/sdk/vimService.wsdl",
    array(
        "trace" => 1,
        "location" => "https://IP:443/sdk/",
        'exceptions' => 1,
        "stream_context" => stream_context_create(
            array(
                'ssl' => array(
                    'verify_peer'       => false,
                    'verify_peer_name'  => false,
                )
            )
        )
    ) 
);

Of course tried this solution but doesn't work.

$oSC = new SoapClient('sap.wsdl', array(
  'local_cert' => 'sap.crt',
  'location' => 'https://sap_address:8102/sap_url/1.0',
  'user_agent' => 'PHP WS',
  'cache_wsdl' => WSDL_CACHE_NONE,
  'trace' => true,
  'exceptions' => true,
  'features' => SOAP_SINGLE_ELEMENT_ARRAYS,
  'soap_version' => SOAP_1_1,
  'stream_context' => stream_context_create(
    array(
      'ssl' => array(
        'verify_peer' => false,
        'verify_peer_name' => false,
      )
    )
  )
));

Try to update php to latest 5.6.9 version and perform debian dist-upgrade to latest libs versions.

What does mean parameter 'local_cert' => 'sap.crt'? Try without it.

http://php.net/manual/en/soapclient.soapclient.php

For HTTPS client certificate authentication use local_cert and passphrase options

Not possible to use without client https certificate. Certificate is without passphrase

This is my production config for https remote air ticket service, and it is working without any cert, just with pass phrase.

$soapParams = [
            'login'                  => $this->request['user'],
            'password'               => $this->request['password'],
            'trace'                  => true,
            'connection_timeout'     => 10,
            'default_socket_timeout' => 10,
            "exceptions"             => true,
            'soap_version'           => SOAP_1_1,
            'cache_wsdl'             => WSDL_CACHE_NONE,
            'location'               => 'https://link/',
            "stream_context"         => stream_context_create(
                [
                    'ssl' => [
                        'verify_peer'      => false,
                        'verify_peer_name' => false,
                    ]
                ]
            )
        ];

This is not my case. I'm using https client certificate (required by server). Your case is ignoring validating https server certificate

Is this still an issue with any of the actively supported PHP
versions[1]?

[1] <https://www.php.net/supported-versions.php>

unable to confirm, not using this anymore, it's over 6 years :)

Thanks for the swift reply!  You are giving us not much
info about the actual problem, though; I mean, how should
we be able to reproduce this, let alone debug?

Given that there are 42 upvotes, there might actually be something
wrong.  Maybe somebody else will provide further details.

> For HTTPS client certificate authentication use local_cert and
> passphrase options
> Not possible to use without client https certificate.
> Certificate is without passphrase

I would have tried an empty passphrase then, rather than not
specifying the option at all.