The bmexec_trans function in kwset.c in grep 2.19 through 2.21 allows local users to cause a denial of service (out-of-bounds heap read and crash) via crafted input when using the -F option.
http://www.securityfocus.com/bid/72281
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
http://www.openwall.com/lists/oss-security/2015/01/22/10
http://rhn.redhat.com/errata/RHSA-2015-1447.html
http://lists.opensuse.org/opensuse-updates/2015-02/msg00037.html
http://git.savannah.gnu.org/cgit/grep.git/commit/?id=83a95bd8c8561875b948cadd417c653dbe7ef2e2