In PHP versions 7.2.x below 7.2.28 7.3.x below 7.3.15 and 7.4.x below 7.4.3 when using file upload functionality if upload progress tracking is enabled but session.upload_progress.cleanup is set to 0 (disabled) and the file upload fails the upload procedure would try to clean up data that does not exist and encounter null pointer dereference which would likely lead to a crash.