Understanding Spring Security CSRF Protection Correctly - Configuration Differences Between REST APIs and Web Apps
Solve the cause of POST returning 403 in Spring Security by understanding the CSRF mechanism. From why `csrf().disable()` is correct for REST APIs, the required settings for Thymeleaf forms, to AJAX support via `CookieCsrfTokenRepository.withHttpOnlyFalse()`, organized with Spring Security 6 Lambda DSL implementation examples.