MOUNTAIN VIEW, Calif.—Mozilla issued an update Thursday for the latest version of its Firefox browser, which fixes a previous security hole.

According to a Mozilla developer blog post Firefox 3.5.1 is now available for Windows, Mac, and Linux users as a free download from Firefox.com. The update improves security and stability, the company said.

"We strongly recommend that all Firefox 3.5 users upgrade to this latest release," the posting said. "If you already have Firefox 3.5, you will receive an automated update notification within 24 to 48 hours. This update can also be applied manually by selecting 'Check for Updates' from the Help menu."

For a list of changes found in the update and more information, see the Firefox 3.5.1 release notes.

Mozilla adds that for anyone who might be using Firefox 2.0.0.x, that version is no longer supported and contains known security vulnerabilities. They suggest an upgrade to 3.5 by downloading Firefox 3.5.1.