The vulnerabilities affect 1.5 versions of Firefox and Thunderbird as well as version 1 of the SeaMonkey suite, Mozilla said in its security advisories. The bugs do not affect Firefox 2.0, the latest version of the browser released late last month.

Submit nowSecurity monitoring companies Secunia and the French Security Incident Response Team, or FrSIRT, deem the issues "highly critical" and "critical," respectively. People who use vulnerable versions of the Mozilla products are urged to upgrade to the fixed versions, both companies said.

C/Net News