A problem with kevent(2) timers has been fixed. If triggered (which can be done by a local unprivileged user), it would result in a kernel hang. Patches for the kernel are available:
5.6: http://ftp.openbsd.org/pub/OpenBSD/patches/5.6/common/032_kevent.patch.sig 5.7: http://ftp.openbsd.org/pub/OpenBSD/patches/5.7/common/018_kevent.patch.sig 5.8: http://ftp.openbsd.org/pub/OpenBSD/patches/5.8/common/005_kevent.patch.sig
