New versions of Firefox will warn users if their version of the Adobe Flash Player plugin is out-of-date.
After downloading the next Firefox release in 3.5.3 or 3.0.1.4, users with out-of-date versions of Flash will be presented with a message saying "you should update Adobe Flash right now", together with a link to the free update on Adobe's website.
Mozilla is focusing on Adobe Flash Player due to its popularity and because many internet users still carry out-of-date versions. It said this was a significant security risk and could potentially cause crashes and stability problems.
Mozilla said it would work with other plugin vendors to provide similar checks for their products in the future.
Adobe's security problems with software have been well documented this year, with multiple flaws seen in Flash Player as well as PDF software Reader and Acrobat.
It also started running a regular security update cycle similar to Microsoft's Patch Tuesday.
