Mozilla on Monday released two new versions of Firefox, 3.5.2 and 3.0.13, to patch two critical security holes.

"We strongly recommend that all Firefox users upgrade to this latest release," Mozilla said in a blog posting about the security issue.

The first vulnerability could let an attacker run arbitrary code on a person's computer by sending specially crafted authentication information called certificate.

The second vulnerability, disclosed last week, involves a flaw in certificate authentication technology that could potentially let an attacker gain access to encrypted information or issue a bogus update to Firefox.