Mozilla's latest version of Firefox is available for downloading again after user privacy could have been violated when it was first released on Tuesday.
Following the discovery of the security vulnerability, the company withdrew version 16 but has now re-released it with, it says, the problem fixed.
The flaw could have enabled sites visited by Firefox to view browsing history, in other words to find out which other web pages its users had visited. The flawed software was online for only a day, after which time Mozilla advised users to use version 15 until the issue was resolved.
Firefox is the second most popular desktop browser in the world, with some 20% share of the market.
A Mozilla spokesman said: "We were quick to recognise the security vulnerability of Firefox 16 and took immediate action to temporarily remove the update from the current installer page. As a precaution we asked Firefox users to revert back to using Firefox 15.0.1 whilst we worked to fix the problem. Firefox 16 was released with updates completely 'throttled', which meant that users were not automatically updated." The spokesman added "We take security issues extremely seriously and were able to address the problem with Firefox quickly with limited impact to our users."
It is fairly common for flaws to be discovered in web browsers, with Microsoft and Google recently having to fix potentially major vulnerabilities in their Internet Explorer and Chrome software.