Hello,
same problem with newest Cursor (2.1.17), but found similar problem Devctonainer issues on 2.0.75 - #11 by LordWaffleman
so after downgrade docker from 29.0.2 to 28.5.2 (docker-ce-28.5.2, docker-ce-cli-28.5.2) helps.
Problem is probably in extension for dev containers.