vim before patch 8.0.0056 does not properly validate values for the 'filetype', 'syntax' and 'keymap' options, which may result in the execution of arbitrary code if a file with a specially crafted modeline is opened.
https://security.gentoo.org/glsa/201701-29
https://lists.debian.org/debian-security-announce/2016/msg00305.html
https://lists.debian.org/debian-lts-announce/2016/11/msg00025.html
https://github.com/vim/vim/releases/tag/v8.0.0056
https://github.com/vim/vim/commit/d0b5138ba4bccff8a744c99836041ef6322ed39a
https://github.com/neovim/neovim/commit/4fad66fbe637818b6b3d6bc5d21923ba72795040
https://anonscm.debian.org/cgit/pkg-vim/vim.git/tree/debian/changelog
http://www.ubuntu.com/usn/USN-3139-1
http://www.securitytracker.com/id/1037338
http://www.securityfocus.com/bid/94478
http://www.debian.org/security/2016/dsa-3722