Pyopenssl Pyopenssl vulnerabilities

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Published CVEs affecting Pyopenssl Pyopenssl: 2 record(s), with affected versions and fixes.
cpe:2.3:a:pyopenssl:pyopenssl

CVE-2026-27459 Critical · 9.8 CWE-120 Mar 17, 2026

pyOpenSSL DTLS cookie callback buffer overflow

pyOpenSSL 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.

CVE-2026-27448 Medium · 5.3 CWE-636 Mar 17, 2026

pyOpenSSL allows TLS connection bypass via unhandled callback exception in set_tlsext_servername_callback

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.