Recently, we had a few tickets dealing with concurrency related to the default session that is used by the connection. Every time a connection API is executed, it may use that session and the memory associated with it. As an example, see WT-13640.

We have doubts about something similar with the __wt_config_getones function that is called by __conn_set_timestamp. This ticket should investigate if a race is possible which would lead to undefined behaviour.