OpenBSD 4.4, 4.5, and 4.6, when running on an i386 kernel, does not properly handle XMM exceptions, which allows local users to cause a denial of service (kernel panic) via unspecified vectors.
http://www.securityfocus.com/bid/36589
http://www.openbsd.org/errata46.html
http://www.openbsd.org/errata45.html
http://www.openbsd.org/errata44.html
http://secunia.com/advisories/36956
http://marc.info/?l=openbsd-security-announce&m=125474331811594