The exploit could allow a malicious user to execute arbitrary code on a remote system and is rated highly critical by Secunia.

“The vulnerability is caused due to an error in the handling of parent windows and can result in a function call using an invalid pointer. This can be exploited to execute arbitrary code when a user e.g. visits a specially crafted web page and closes opened pop-up windows” says the Secunia security advisory.

The vulnerability affects both Mac OS X and Windows versions of the browser. Apple is yet to release an update to close the flaw.

The update takes the browser to 10.52, and is mostly a stability fix for Windows, with many bug fixes. A full list of changes can be found in the changelog.

Opera 10.52 on Mac finally sees the arrival of the Carakan JavaScript engine, Vega graphics library, and Opera Presto 2.5 browser engine.

Early benchmark results also look promising, showing that Opera is on par with or better than Google Chrome 5 (beta) for Mac. Full benchmarks can be seen on the Choose Opera blog.

The Opera browser can be downloaded from the Opera website.

This figure includes 50 million users on Windows, Mac and Linux, plus another 50 million users browsing the web with Opera Mini on their mobile devices.

100 million users comes after a staggering 30% jump in desktop users from the same time last year, mostly attributed to the release of Opera 10.x browsers.

“Our focus on speed, security, innovation and usability continues to yield results. We always listen to the needs and wants of our users, and they reward us by choosing Opera,” said Jon von Tetzchner, Co-founder, Opera Software.

Congratulations to Opera on the achievement, and new users can download Opera for their computer or mobile device from the Opera website.

The above numbers are a sample of the percentages of each country downloads of Opera 10.50 that originates from the Choice Screen, as part of the total Opera 10.50 numbers for desktop.

Full stats for European Union countries are available from the Choose Opera Blog.

A better idea of how the browser ballot screen in the European Union has affected worldwide market share will be known at the end of March.

Not much has changed so far, but Windows versions will now use the default download folder for downloading files, while the Mac version is now more stable with extensions.

Linux versions now include support for desktop notifications, along with improved support for complex text such as Arabic and Hebrew.

Being development versions, they are prone to instability and crashes. There is currently one known bug in the Mac version, which will crash the browser when a user clears the cookies.

Users can jump on the dev channel version of Google Chrome by following instructions on the Chromium website.

The ballot screen will be pushed out to users of Windows XP, Vista, and 7 via Windows Update for users in the EU and neighbouring countries.

The ballot screen is required to be in place for at least the next 5 years, or Microsoft face fines of up to 10% of it’s world wide turnover.

On release, the ballot screen is set to include the 5 major browser – Internet Explorer, Firefox, Safari, Chrome and Opera – all in a random order. Users will also be able to scroll down the screen to choose less popular browsers. These include AOL, Maxthon, K-Meleon, Flock, Avant Browser, Sleipnir and Slim Browser.

The list of browsers is set to be reviewed every 6 months.

“We hope this closes a long chapter in a sometimes uneasy relationship with the Commission, and we hope it opens a new one,” said Competition Commissioner Neelie Kroes.

The ballot screen is expected to be pushed out to users in the first part of 2010.

“Opera 10 showcases a sleek new design coupled with our new Turbo technology, which keeps Web pages loading lightning fast, even if your connection slows down” says the spiel on Opera’s homepage.

Other new features include an in-line spell check, full Acid3 compliance and mouse gestures.

A full run down on features and download links for Windows, OS X, and Linux can be found on the Opera 10 site.

“The v8 team did some amazing work this quarter building a working 64-bit port.  After a handful of changes on the Chromium side, I’ve had Chromium Linux building on 64-bit for the last few weeks” said Google Chrome Software Engineer Dean McNamee.

The new builds can be downloaded from here, with build instructions also being available for Linux users.

A Windows and Mac version are set to follow.

The change will be pushed out via Windows Update to all users in the EU.

“Microsoft will distribute a Ballot Screen software update to users within the EEA of Windows XP, Windows Vista and Windows Client PC Operating Systems, by means of Windows Update as described hereafter: A software update enabling the Ballot Screen to be displayed will be made available to all current and future users of Windows XP and Windows Vista who receive updates from Windows Update. For Windows XP and Windows Vista users the Ballot Screen update will first be made available between 3 and 6 months after the adoption of the Commission’s decision.”

There is still no word on when the final decision will be made.

Silverlight 3.0 includes over 50 new features, including graphic processing unit (GPU) acceleration, 3D support, H.264 video support and out-of-the-browser capabilities to Silverlight.

A full list of features can be read on the Silverlight website. Silverlight 3 is available for Windows and Mac OS X today.