A day after launching Netscape 8 and touting the browser's security features, Netscape has released an update to fix several serious security flaws.

The original Netscape 8, released early Thursday, is based on version 1.0.3 of the open-source Firefox browser. Netscape thought the new browser was immune to security vulnerabilities in the Firefox software that were fixed last week in Firefox 1.0.4. It turns out Netscape 8 is vulnerable.

"We had been misinformed by an external security vendor that the Firefox security issues did not affect us," Netscape spokesman Andrew Weinstein said Friday. "Within hours of discovering that the vendor was not accurate, we had addressed those issues and posted an updated version of the browser."

Late on Thursday, the software maker posted Netscape version 8.0.1, which includes fixes for the problems. It plans to push an update out to people who installed the original Netscape 8. However, the company is still working on its update mechanism, so in the meantime people have to go to the Netscape.com Web site to get the patched browser, Weinstein said.