PVS-Studio warning V595 for NetXMS

DWORD SNMP_PDU::encodeV3SecurityParameters(
  BYTE *buffer, DWORD bufferSize,
  SNMP_SecurityContext *securityContext)
{
  BYTE securityParameters[1024], sequence[1040];
  DWORD bytes;
  DWORD engineBoots =
    securityContext->getAuthoritativeEngine().getBoots();
  DWORD engineTime =
    securityContext->getAuthoritativeEngine().getTime();

  if ((securityContext != NULL) &&
      (securityContext->getSecurityModel() ==
       SNMP_SECURITY_MODEL_USM))
  {
  ....
}

This suspicious code was found in NetXMS project by PVS-Studio static code analyzer.
Warning message is:
V595 The 'securityContext' pointer was utilized before it was verified against nullptr. Check lines: 1159, 1162. pdu.cpp 1159

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/