FlatBSON Duplicate Field Index Drift

An issue in MongoDB Server's time-series collection implementation allows an authenticated user with database write privileges to trigger an out-of-bounds memory write in the mongod process. The issue results from an inconsistency in the internal field-name-to-index mapping within the time-series bucket catalog. Under certain conditions this can result in arbitrary code execution. This issue impacts MongoDB Server v5.0 versions prior to 5.0.33, v6.0 versions prior to 6.0.28, v7.0 versions prior to 7.0.34, v8.0 versions prior to 8.0.23, v8.2 versions prior to 8.2.9 and v8.3 versions prior to 8.3.2.