A NULL pointer dereference in the SQLite Session Extension in SQLite 3.53.1 and SQLite trunk builds before check-in e807d4e3798efd53 allows an attacker who can supply a malformed changeset blob to cause a denial of service. The issue occurs when sqlite3changeset_apply_v3() applies a corrupt changeset and reaches sqlite3_value_type() with a NULL sqlite3_value pointer.