Sony has closed a loophole that allowed users to run software that enables pirated games to be played on the PS3 console.
The update blocks the PSJailbreak and PSGroove applications.
Mathieu Hervais, one of the developers behind PSGroove, told BBC News that it was "safer not to update" if users wished to continue using the hacks.
Sony won a court order in early September banning the distribution of the PSJailbreak dongle.
The update is the latest step in Sony's ongoing battle against the commercial dongle - PS Jailbreak - that allows users to play pirated software. It also targets open source code, known as PSGroove, which allows homemade games to be played on the console.
While the PSGroove software was not originally intended to allow the playing of pirated games, as PSJailbreak does, it has already been modified by other hackers to permit the practice.
It is the continuation of a cat-and-mouse game between hackers and the electronics giant, which started when PSJailbreak first appeared for sale on website.
The USB dongle was the first hardware hack of Sony's secure games console.
Sony has since obtained a court injunction preventing the distribution of the PSJailbreak dongle in Australia.
The firm has also filed a US lawsuit against Zoomba, a firm that runs a site selling the device. Distributors in the Netherlands have also told the BBC that they have received court documents banning the sale of the dongles.
However, Sony has now decided to tackle the problem head-on by releasing a software update for the consoles that block the hacks.
The new patch received a mixed reception from the gaming community, with some users praising Sony for its prompt action, while others were more critical.
"Every time there is an update, it's a security patch I don't care about," wrote one.
"Give me something that will keep me occupied like more visuals on the music player, a way to delete trophies for a game I don't have anymore, backward compatibility for PS2 games, better video chat.
"You guys don't take to many suggestions from your players. If you listen, I mean really listen, to the ideas you will be top," they added.
Mr Hervais told BBC News that it did yet know how Sony fixed the security flaw.
Sony declined to comment on the specifics of the update, but a spokesman told BBC News: "Since this is an overall security related issue, we will not be providing further commentary to this case.
"But as we always have, we will continue to take necessary actions to both hardware and software to protect the intellectual content provided on the PlayStation 3."