The September 22 update for Street Fighter V–containing Urien, and a host of other changes–caused a lot of headaches for PC users, bringing about technical issues and security concerns that prompted Capcom to roll back part of the 1.09 update on PC.
Capcom has since taken to the Steam Community page to confirm to users that the quick-fix patch offered on September 23 indeed removes the aforementioned security risk, and encourages PC users to install it. They also indicate that a future tool, available in the next few days, will automatically remove the offending insecure file (presumably Capcom.sys, reported to remain in the system folder post-rollback, prompting many users to remove it manually).
Read their original statement on the Steam Community here.
Source: Steam Community via Street Fighter (Twitter)