Network Security Services is a set of libraries designed to support the cross-platform development of security-enabled client and server applications. Netscape Portable Runtime provides platform independence for non-GUI operating system facilities. A race condition was found in the way NSS verified certain certificates. A remote attacker could use this flaw to crash an application using NSS or, possibly, execute arbitrary code with the privileges of the user running that application. Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Tyson Smith and Jesse Schwartzentruber as the original reporters. All NSS users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, applications using NSS must be restarted for this update to take effect.