Adobe released on Wednesday an update that fixes vulnerabilities in its widely used Reader document viewing program. Users are urged to upgrade to version 8.1.2, available for download on Adobe's Web site.

Adobe has not given out details of the vulnerabilities, even though the company has a section on its Web site detailing security advisories for Reader. That could indicate that the vulnerabilities are fairly serious and could result in a compromised PC, said Thomas Kristensen, chief technical officer for Secunia, a security vendor in Denmark.