How do I recover from an incorrect bulk product update?

Stop further imports or edits, identify exactly which records and fields changed, and restore from the most recent trusted export, backup or source system wherever possible. Do not blindly re-import an entire catalogue if only a subset was affected. Compare identifiers and timestamps to isolate the damage. After recovery, document why the update failed and add a preventive control—such as a sample test, validation rule, approval step or automated backup—before running the same kind of bulk change again.