mysqlclient 2.2.5 version bug: django.db.utils.OperationalError: (2026, 'TLS/SSL error: Server certificate validation failed. A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider. Error 0x800B0109(CERT_E_UNTRUSTEDROOT)')

[xionglilong]

Describe the bug

i use 2.2.4 version is normal, bug use new version 2.2.5 in django, it is ssl error, I can't skip this test.

error result:

django.db.utils.OperationalError: (2026, 'TLS/SSL error: Server certificate validation failed. A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider. Error 0x800B0109(CERT_E_UNTRUSTEDROOT)')

Environment

No response

How did you install libmysqlclient libraries?

i use Windows 11

What version of mysqlclient do you use?

django 5.1.1
mysqlclient 2.2.5

Docker command to start MySQL server

No response

Minimum but complete code to reproduce

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.mysql',
        'NAME': "xxx",
        'USER': 'web-django',
        'PASSWORD': 'xxx',
        'HOST': "x.x.x.x" if not os.getenv('PRODUCTION') else "172.17.0.1",
        'PORT': xxxx,

        'OPTIONS': {
            'charset': 'utf8mb4',
            'init_command': "SET sql_mode='STRICT_TRANS_TABLES'",
        },
    },
    'sqlite3': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    },
}

Schema and initial data required to reproduce.

Watching for file changes with StatReloader
Performing system checks...

System check identified no issues (0 silenced).
Exception in thread django-main-thread:
Traceback (most recent call last):
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\base\base.py", line 275, in ensure_connection
    self.connect()
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\base\base.py", line 256, in connect
    self.connection = self.get_new_connection(conn_params)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\mysql\base.py", line 256, in get_new_connection
    connection = Database.connect(**conn_params)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\MySQLdb\__init__.py", line 121, in Connect
    return Connection(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\MySQLdb\connections.py", line 195, in __init__
    super().__init__(*args, **kwargs2)
MySQLdb.OperationalError: (2026, 'TLS/SSL error: Server certificate validation failed. A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider. Error 0x800B0109(CERT_E_UNTRUSTEDROOT)')

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\xiong\AppData\Local\Programs\Python\Python312\Lib\threading.py", line 1075, in _bootstrap_inner
    self.run()
  File "C:\Users\xiong\AppData\Local\Programs\Python\Python312\Lib\threading.py", line 1012, in run
    self._target(*self._args, **self._kwargs)
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\utils\autoreload.py", line 64, in wrapper
    fn(*args, **kwargs)
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\core\management\commands\runserver.py", line 136, in inner_run
    self.check_migrations()
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\core\management\base.py", line 581, in check_migrations
    executor = MigrationExecutor(connections[DEFAULT_DB_ALIAS])
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\migrations\executor.py", line 18, in __init__
    self.loader = MigrationLoader(self.connection)
                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\migrations\loader.py", line 58, in __init__
    self.build_graph()
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\migrations\loader.py", line 235, in build_graph
    self.applied_migrations = recorder.applied_migrations()
                              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\migrations\recorder.py", line 89, in applied_migrations
    if self.has_table():
       ^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\migrations\recorder.py", line 63, in has_table
    with self.connection.cursor() as cursor:
         ^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\base\base.py", line 316, in cursor
    return self._cursor()
           ^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\base\base.py", line 292, in _cursor
    self.ensure_connection()
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\base\base.py", line 274, in ensure_connection
    with self.wrap_database_errors:
         ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\utils.py", line 91, in __exit__
    raise dj_exc_value.with_traceback(traceback) from exc_value
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\base\base.py", line 275, in ensure_connection
    self.connect()
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\base\base.py", line 256, in connect
    self.connection = self.get_new_connection(conn_params)
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\utils\asyncio.py", line 26, in inner
    return func(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\django\db\backends\mysql\base.py", line 256, in get_new_connection
    connection = Database.connect(**conn_params)
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\MySQLdb\__init__.py", line 121, in Connect
    return Connection(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "D:\project\web-django\xinshengyuan-web-django\.venv\Lib\site-packages\MySQLdb\connections.py", line 195, in __init__
    super().__init__(*args, **kwargs2)
django.db.utils.OperationalError: (2026, 'TLS/SSL error: Server certificate validation failed. A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider. Error 0x800B0109(CERT_E_UNTRUSTEDROOT)')

Commands, and any other step required to reproduce your issue.

No response

[methane]

Can you try the wheel in this artifacts?
https://github.com/PyMySQL/mysqlclient/actions/runs/11480212164

[spapas]

Hey @methane I used the wheel you mentioned and 2.2.5 works fine for me.

[mpibpc-mroose]

same for me: the artifact fixes the problem

[GitRon]

Thx @methane! What's the way to go with this knowledge? Will there be a new release with that artifact?

[taozuhong]

Set environment could stop this issue:
export MARIADB_TLS_DISABLE_PEER_VERIFICATION=1