The vulnerability is "highly critical" according to an advisory released by the Danish company late on Tuesday. Version 6.2.3 and 7.2 of Netscape are affected and other versions may also be susceptible, the company said.
The flaw could allow a hacker to launch a buffer overflow attack, which could crash the browser or enable the attacker to execute code on the compromised system. A patch has not been created, according to Secunia.
Netscape representatives did not immediately return calls seeking comment.
Secunia's advice for dealing with the issue is to "use another product."
