1. What versions are you using?
   Oracle: 19.3.0-ee (in docker, note the bug does not appear with another image based on 18.4.0-xe)
   platform.platform: Linux-5.15.0-67-generic-x86_64-with-glibc2.35
   sys.maxsize > 2**32: True
   platform.python_version: 3.9.13
   oracledb.version: 1.3.0

2. Is it an error or a hang or a crash?
   Error.

3. What error(s) or behavior you are seeing?
   oracledb.exceptions.InternalError: DPY-5000: internal error: unknown protocol message type 10

4. Does your application call init_oracle_client()?
   No

5. Include a runnable Python script that shows the problem.
   import oracledb
   import os

un = os.environ.get('USER_NAME')
pw = os.environ.get('PASSWORD')
cs = os.environ.get('CONNECT_STRING')
oracledb.connect(user=un, password=pw, dsn=cs, disable_oob=True)

Traceback (most recent call last):
File "/mnt/vm/BK/tests/oracle_connect.py", line 8, in
oracledb.connect(user=un, password=pw, dsn=cs, disable_oob=True)
File "/mnt/vm/BK/diracos/lib/python3.9/site-packages/oracledb/connection.py", line 1008, in connect
return conn_class(dsn=dsn, pool=pool, params=params, **kwargs)
File "/mnt/vm/BK/diracos/lib/python3.9/site-packages/oracledb/connection.py", line 130, in init
impl.connect(params_impl)
File "src/oracledb/impl/thin/connection.pyx", line 314, in oracledb.thin_impl.ThinConnImpl.connect
File "src/oracledb/impl/thin/connection.pyx", line 202, in oracledb.thin_impl.ThinConnImpl._connect_with_params
File "src/oracledb/impl/thin/connection.pyx", line 173, in oracledb.thin_impl.ThinConnImpl._connect_with_description
File "src/oracledb/impl/thin/connection.pyx", line 114, in oracledb.thin_impl.ThinConnImpl._connect_with_address
File "src/oracledb/impl/thin/protocol.pyx", line 229, in oracledb.thin_impl.Protocol._connect_phase_two
File "src/oracledb/impl/thin/protocol.pyx", line 343, in oracledb.thin_impl.Protocol._process_message
File "src/oracledb/impl/thin/protocol.pyx", line 322, in oracledb.thin_impl.Protocol._process_message
File "src/oracledb/impl/thin/messages.pyx", line 292, in oracledb.thin_impl.Message.process
File "src/oracledb/impl/thin/messages.pyx", line 179, in oracledb.thin_impl.Message._process_message
File "/mnt/vm/BK/diracos/lib/python3.9/site-packages/oracledb/errors.py", line 118, in _raise_err
raise exc_type(_Error(message)) from cause
oracledb.exceptions.InternalError: DPY-5000: internal error: unknown protocol message type 10

Wireshark recognize the last TNS message, 1.2.x get the same packet and is also happy (PYO_DEBUG_PACKETS=1 output is attached, one from 1.2.0 another from 1.3.0)

trace_failed.txt
trace_ok.txt