Vulnerability Details CVE-2026-27448
pyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 0.14.0 and prior to version 26.0.0, if a user provided callback to `set_tlsext_servername_callback` raised an unhandled exception, this would result in a connection being accepted. If a user was relying on this callback for any security-sensitive behavior, this could allow bypassing it. Starting in version 26.0.0, unhandled exceptions now result in rejecting the connection.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 16.9%
CVSS Severity