Users of the latest version of the open source Firefox browser face two “extremely critical” security holes relating to cross-site scripting and hacker remote access.
Security researcher Secunia has reported the “proof of concept” flaws and said that they are extremely critical as exploited code has been circulated on the internet.
Mozilla has also changed its web update system to help reduce the risk of the security holes.
Mozilla said it was not aware of any exploits of the vulnerabilities among Firefox users.
There have been over 44m downloads of recently launched Firefox, which is aiming to challenge the dominance of Microsoft’s Internet Explorer, which has around 90% of the browser market.