Mozilla has temporarily taken Firefox 16 off its installer page after the exposition of a security weakness.

It was announced in a blog post written last night that a fix for the vulnerability is currently under construction, and is expected to be made available later today.

"The vulnerability could allow a malicious site to potentially determine which websites users have visited and have access to the URL or URL parameters," wrote Mozilla's director of security assurance, Michael Coates. "At this time we have no indication that this vulnerability is currently being exploited in the wild."

When the fix is completed and the patches are issued, they will be automatically applied to Firefox 16. However, in the meantime users have the option to downgrade to version 15.0.1, which remains unchanged.

The unsavoury news comes just days after Firefox 16's 9 October release.