Mozilla has released Firefox 3.5.1 which fix several security and stability issues.

One security vulnerability is rated as critical, and could allow a remote attacker to gain control of a users PC.

Firefox 3.5.1 can be downloaded from the Firefox website, and will automatically be pushed out to existing Firefox 3.5 users. A full list of changes can be found in the release notes.

Security firm Secunia are warning of a zero-day securty exploit which has been discovered in Firefox 3.5 allowing a milicious site to execute arbituary code.

“The vulnerability is caused due to an error when processing JavaScript code handling e.g. ‘font’ HTML tags and can be exploited to cause a memory corruption” said a spokesperson from Secunia.

No word from Mozilla on a fix yet, but Firefox 3.5.1 will likely be released in the coming days to address the issue.

More news has surfaced about multi-process support for Firefox, with a prototype now completed.

Multi-process support gives each tabs, window, and plugins its own process. Browsers such as Google Chrome and Internet Explorer 8 already support this feature.

Benjamin Smedberg has blogged about the benefits of multi-processes:

• Increased stability: if a plugin or webpage tries to use all the processor, memory, or even crashes, a process can isolate that bad behavior from the rest of the browser.
• Performance: By splitting work up among multiple processes, the browser can make use of multiple processor cores available on modern desktop computers and the next generation of mobile processors. The user interface can also be more responsive because it doesn’t need to block on long-running web page activities.
• Security: If the operating system can run a process with lower privileges, the browser can isolate web pages from the rest of the computer, making it harder for attackers to infect a computer.

Firefox developer Chris Jones has posted a screencast demoing the new technology.

No word on a final release date yet, but we may see this technology in production version some time in late 2010. Currently the team are focusing on Windows and Linux versions.

Firefox 3.5 was downloaded more than 5 million times in 24 hours, but this is still 3 million less than the 8 million downloads when Firefox 3 was released.

With the release of Firefox 3.5, Mozilla have provided real time Firefox download information. Current downloads totals for 3.5 are nearing 9 million in just 2 days.

Overall Firefox downloads are estimated to be over 900 million.

Mozilla has finally released Firefox 3.5 final, the next installment in the Firefox series.

Firefox 3.5 is more than twice as fast as Firefox 3, and 12 times faster than Firefox 2.

New features includes support for HTML5 audio and video tags, private browsing, faster JavaScript engine and of course better stability and security.

A full list of changes can be found in the release notes, while the new browser can be downloaded from Firefox.

Mozilla has released Firefox 3.5 release candidate (RC) 3 overnight, just days after RC2.

The new build fixes a few bugs and increases overall stability. Changes can be found in the release notes.

The browser can be downloaded from the Firefox beta website, and a final release is expected next week.

Mozilla has released Firefox 3.5 Release Candidate 2 (RC2). With minimal changes since RC1 last week, the end is near for Firefox 3.5.

Firefox 3.5 final is still scheduled before the end of June.

A full list of changes can be found in the release notes. The new browser will be automatically downloaded for RC1 users, or can be downloaded directly from the Mozilla Beta website.

Included in Release Candidate 1 builds of Firefox, Mozilla has released the final iteration of the new Firefox 3.5 logo.

The icon was created by Anthony Piraino from the Iconfactory, and went through a total of 14 iterations over several weeks.

The new icon has a stronger 3D feel to it, with much more detail in the foxes tail.

The new logo is available in several sizes and formats and can be downloaded from the Mozilla Wiki.

Mozilla has just released Firefox 3.5 Release Candidate (RC) to the web.

Other than better stability, there doesn’t seem to be much new under the hood. A full list of changes since Beta 4 can be found in the release notes.

The browser is available on all major platforms from the Firefox Beta website. Existing Beta 4 users will have the update pushed out to them automatically.