Inefficient Regular Expression Complexity
A regular expression based DoS vulnerability in activesupport versions through 188.8.131.52, 6.0.0.beta1 through 6.1.7, and 7.0.0.alpha1 through 7.0.4. A specially crafted string passed to the "underscore" method can cause the regular expression engine to enter a state of Catastrophic Backtracking. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability.
CWE-1333 - Inefficient Regular Expression Complexity
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.