9.12.1 / 2026-11-09

• perf(update): avoid quadratic ancestor lookup in update validators and validate nested array subdocs once #16586 https://github.com/Re-cool
• perf: keep lib/ source within Latin-1 #16681 orgads
• perf(map): avoid quadratic concat() when creating a MongooseMap from an object #16677 ptweezy
• fix(array): keep earlier pushed values when push() is called again with $each #16619 #16618 maxymlyskov
• fix(model+query): handle inherited read preference and read concern on cloned queries #16668 #16632
• fix(timestamps): set timestamps on subdocs pushed via array filters #16615 #8809 vaidehi-snk
• fix(model): validate paths under a nested path passed to Model.validate() #16653 NotAFlightRisk
• fix(update): skip array-level validators for $pull with $in #16666 AnkitKumar61
• fix(cursor): finish destruction after terminal initialization #16612 IbrahimHafez1