The wrap_lines_smart function in ass_render.c in libass before 0.13.4 allows remote attackers to cause a denial of service (out-of-bounds read) via unspecified vectors, related to "0/3 line wrapping equalization."
https://security.gentoo.org/glsa/201702-25
https://github.com/libass/libass/releases/tag/0.13.4
https://github.com/libass/libass/commit/f4f48950788b91c6a30029cc28a240b834713ea7
https://bugzilla.redhat.com/show_bug.cgi?id=1381960
http://www.securityfocus.com/bid/93358
http://www.openwall.com/lists/oss-security/2016/10/05/2
http://lists.opensuse.org/opensuse-updates/2016-12/msg00068.html