Is the update and application of new AWAF attack signatures "Service Affecting"?

Hi Wasfi_Bounni , 
Yes , it may impcat you. 

and not it depends : 

1. you want to enforce signtaures immediately. ( may impact you and produce false positives ) 
2. you can keep these signature under learning for a while ( Readness period "default 7 days" ) 

Open ( Security >> Application security >> Learning and blocking settinngs >>> Attack signatures ) 

- If you want to enforce it directley : 
open this : 

Make sure ( you're selecting enforce updated rule immediately ...... ). 
>>> by doing this all newly updated signature will be enforced directly. 

- If you want to keep updated signature for a while and in learning and after checking your learning suggestion to take your decision : 

modify your configuration like this : 

>>> performing this shoud put your newly signatures in statging waiting the ( Readness period to be fininshed ) to be ready to be enforced and you will work on parallel on learning suggestions ( Accept / delete suggestions ) based on your analysis in suggestions collected from requests samples. 

I hope this helps you 🙂