Update dependency pyOpenSSL to v26 [SECURITY]

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
pyOpenSSL (source)	25.1.0 → 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

v25.3.0

Compare Source

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

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

Changes:
^^^^^^^^

• Maximum supported cryptography version is now 46.x.

v25.2.0

Compare Source

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

• The minimum cryptography version is now 45.0.7.

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

Changes:
^^^^^^^^

• pyOpenSSL now sets SSL_MODE_ACCEPT_MOVING_WRITE_BUFFER on connections by default, matching CPython's behavior.
• Added OpenSSL.SSL.Context.clear_mode.
• Added OpenSSL.SSL.Context.set_tls13_ciphersuites to set the allowed TLS 1.3 ciphers.
• Added OpenSSL.SSL.Connection.set_info_callback

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Configuration

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[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.42%. Comparing base (9642067) to head (01543fc).

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #2931   +/-   ##
=======================================
  Coverage   90.42%   90.42%           
=======================================
  Files         231      231           
  Lines       14939    14939           
=======================================
  Hits        13509    13509           
  Misses       1430     1430           

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