The module-level ssl.wrap_socket() was marked as deprecated in Python 3.7 and fully removed in Python 3.12. Programs should create a SSLContext using ssl.create_default_context() and use the context instance's .wrap_socket() method.

In other words, your mysql.connector has not been updated for Python 3.12 compatibility. According to MySQL docs you need mysql.connector version >=8.2.0 for Python 3.12.

You might have better luck using the MySQLdb module, which is available via pip as the "mysqlclient" package. It uses the same C libraries (libmysqlclient or libmariadbclient) and supports TLS.

Per the mysql-connector-python package bug report linked by steeldriver, the cause of the issue appears to be that Python 3.12 removed ssl.wrap_socket (it had been marked deprecated since Python 3.7), but the version of the Python mysql.connector package provided by Ubuntu's python3-mysql.connector package is an old version incompatible with Python 3.12 that expects ssl.wrap_socket to still exist.

From the upstream mysql-connector-python repo, it appears that support for Python 3.12 was first introduced in version v8.2.0. But, in Ubuntu 24.04 LTS, if we apt install python3-msql.connector, inspecting /usr/lib/python3/dist-packages/mysql/connector/version.py and /usr/lib/python3/dist-packages/mysql/connector/network.py shows that it is version v8.0.15, which is not documented as supporting Python 3.12, and attempts to call ssl.wrap_socket are still present inside network.py. So we expect that not to work.

Here's an example following Steeldriver's suggested workaround, avoiding use of the globally installed mysql.connector package provided by ubuntu's python3-mysql.connector package that is incompatible with python3.12, and instead installing a newer version of that package from pypi to an isolated python virtual environment:

$ cat issue.sh

#! /usr/bin/env bash
set -uxo pipefail

python3 -m venv venv
source venv/bin/activate
python3 -m pip install --upgrade mysql-connector-python
python3 test.py

$ cat test.py
import mysql.connector
db = mysql.connector.connect(host="localhost", user="ray", password="...")
print(db)
exit(0)

Run it with chmod +x ./issue.sh && ./issue.sh.

When I run this, it installs version 9.5.0 of the msql-connector-python package.

Don't name your script ssl.py, because when you name your script ssl.py and you do import ssl you're importing this same script .

As of 0.10, Werkzeug doesn't support OpenSSL contexts anymore. This decision was made because it is easier to support ssl.SSLContext across Python versions. Your option to re-write this code is this one:

if __name__ == "__main__":
    context = ('cert.crt', 'key.key')
    app.run(host='0.0.0.0', port=80, ssl_context=context, threaded=True, debug=True)

See http://werkzeug.pocoo.org/docs/latest/serving/ for all possibilities.