Race condition
A race condition or race hazard is the behavior of an electronics, software, or other system where the system's substantive behavior is dependent on the sequence or timing of other uncontrollable events. It becomes a bug when one or more of the possible behaviors is undesirable.
Time of check to time of use
In software development, time of check to time of use (TOCTOU, TOCTTOU or TOC/TOU) is a class of software bugs caused by changes in a system between the "checking" of a condition (such as a security credential) and the "use" of the results of that check. This is one example of a race condition.