Regular expression denial of service (ReDoS) is a type of Denial of Service attack that can occur when regular expressions are used in a way that causes the regex engine to take an excessive amount of time to process, resulting in catastrophic backtracking. This vulnerability was recently found to have increased by 143% in the last year alone, according to a recent state of open source security report. A ReDoS attack can be triggered when an attacker passes a string that causes the regex engine to backtrack throughout all possibilities before failing, resulting in a denial of service. The ms package is vulnerable to this type of attack, and exploiting it can cause a significant delay or even bring the system down.