Pyca Pyopenssl vulnerabilities
2 vulnerabilities
Known vulnerabilities in Pyca Pyopenssl, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.
PrioritiseCVE-2026-27459pyca · pyopenssl +60 morepyOpenSSL DTLS cookie callback buffer overflowpyOpenSSL is a Python wrapper around the OpenSSL library. Starting in version 22.0.0 and prior to version 26.0.0, if a user provided callback to `set_cookie_generate_callback` returned a cookie value greater than 256 bytes, pyOpenSSL would overflow an OpenSSL provided buffer. Starting in version 26.0.0, cookie values that are too long are now rejected.CVSS9.8CriticalEPSS0.75%RoutineCVE-2026-27448pyca · pyopenssl +64 morepyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callbackpyOpenSSL 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.CVSS5.3MediumEPSS0.26%