Integer overflow in the PointGFp constructor in Botan before 1.10.11 and 1.11.x before 1.11.27 allows remote attackers to overwrite memory and possibly execute arbitrary code via a crafted ECC point, which triggers a heap-based buffer overflow.
https://security.gentoo.org/glsa/201612-38
http://www.debian.org/security/2016/dsa-3565