Regex Bypass

Regex101

If we want to bypass a regex, first we need to understand it. for that i will be going to use the below link

regex101: build, test, and debug regexregex101

lets say we have the following regex

^([a-zA-Z0-9_.-])+@(([a-zA-Z0-9-])+.)+([a-zA-Z0-9]{2,4})+$

i will paste this to regex101 and try to understand it

now i will try to add a random email address to see wether i can bypass the regex or not, and i can see that my email has been caught by the regex

now i will try to bypass it using the following email

jjjjjjjjjjjjjjjjjjjjjjjjjjjj@ccccccccccccccccccccccccccccc.55555555555555555555555555555555555555555555555555555555.

and now regex has been bypassed

JEX.IM

We can use the Second website to understand the regex

Regulex：JavaScript Regular Expression Visualizer

so i can paste the same regex used above and understand it