A vulnerability in Python's ssl.SSLContext.wrap_bio() method allows silent skipping of certificate hostname verification when the server_hostname argument is not provided, despite SSLContext.check_hostname being set to True. This can cause programs to mistakenly believe hostname verification succeeded, potentially weakening SSL/TLS security. The issue affects Python versions prior to 3.11.6-44.oe2403sp1. Mitigation can be achieved by passing a valid non-empty server_hostname parameter to relevant APIs. The vulnerability is fixed in Python 3.11.6-44.oe2403sp1, where missing server_hostname causes a ValueError instead of silent skipping.