Search: CVE-2026-19553

CVE-2026-19553 is a vulnerability in Python's CPython ssl module where SSLContext.wrap_bio() does not require the server_hostname argument to be non-None when SSLContext.check_hostname is enabled. This causes hostname verification to be silently skipped if server_hostname is not supplied, potentially leading to a false sense of security. The issue affects multiple Python versions prior to specific fixed releases. Mitigation does not require patching but involves passing a valid non-empty server_hostname to relevant APIs. The patch changes the behavior to raise a ValueError instead of silently skipping verification.