Botan 1.11.x before 1.11.29 does not enforce TLS policy for (1) signature algorithms and (2) ECC curves, which allows remote attackers to conduct downgrade attacks via unspecified vectors.
https://security.gentoo.org/glsa/201701-23
http://marc.info/?l=botan-devel&m=145852488622892&w=2
http://lists.fedoraproject.org/pipermail/package-announce/2016-May/183669.html