(...) Any Firefox 1.0.x and Mozilla 1.x users who have not upgraded to versions 1.0.7 and 1.7.12 respectively are advised to do so immediately (...). It should be noted that Firefox 1.5 Beta 1 is vulnerable to the flaw, so users should either revert to an end-user release of Firefox (that is, 1.0.7) or update to a more recent Firefox nightly build from the 1.8 branch. SeaMonkey 1.0 Alpha is not affected by the vulnerability (but the Linux version is at risk from the Linux command line URL parsing security bug).