Buffer overflow in the calc_coeff function in libass/ass_blur.c in libass before 0.13.4 allows remote attackers to cause a denial of service via unspecified vectors.
https://security.gentoo.org/glsa/201702-25
https://github.com/libass/libass/releases/tag/0.13.4
https://github.com/libass/libass/pull/240/commits/08e754612019ed84d1db0d1fc4f5798248decd75
https://bugzilla.redhat.com/show_bug.cgi?id=1381960