Not sure if this has been discussed earlier, but I would consider proper integration tests as a preventive mechanism to broken access control. By writing tests for access controls you will get a guarantee that it will not happen, and you will (should) break the build and not deploy the vulnerable changes to production. This of course requires a thorough test suite, with all the "bad" cases covered, and also mechanisms to detect when new API endpoints are added without test coverage.
Not sure if this has been discussed earlier, but I would consider proper integration tests as a preventive mechanism to broken access control. By writing tests for access controls you will get a guarantee that it will not happen, and you will (should) break the build and not deploy the vulnerable changes to production. This of course requires a thorough test suite, with all the "bad" cases covered, and also mechanisms to detect when new API endpoints are added without test coverage.