chore(deps): update dependency pyopenssl to v26 [security]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
pyOpenSSL (source)	==25.3.0 → ==26.0.0

GitHub Vulnerability Alerts

CVE-2026-27448

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.

Unhandled exceptions now result in rejecting the connection.

Credit to Leury Castillo for reporting this issue.

CVE-2026-27459

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.

Cookie values that are too long are now rejected.

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Release Notes

pyca/pyopenssl (pyOpenSSL)

v26.0.0

Compare Source

Backward-incompatible changes:
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

• Dropped support for Python 3.7.
• The minimum cryptography version is now 46.0.0.

Deprecations:
^^^^^^^^^^^^^

Changes:
^^^^^^^^

• Added support for using aws-lc instead of OpenSSL.
• Properly raise an error if a DTLS cookie callback returned a cookie longer than DTLS1_COOKIE_LENGTH bytes. Previously this would result in a buffer-overflow. Credit to dark_haxor for reporting the issue. CVE-2026-27459
• Added OpenSSL.SSL.Connection.get_group_name to determine which group name was negotiated.
• Context.set_tlsext_servername_callback now handles exceptions raised in the callback by calling sys.excepthook and returning a fatal TLS alert. Previously, exceptions were silently swallowed and the handshake would proceed as if the callback had succeeded. Credit to Leury Castillo for reporting this issue. CVE-2026-27448

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