nixpkgs

2ddaccba - tnef: 1.4.17 -> 1.4.18 (security)

tnef: 1.4.17 -> 1.4.18 (security) Backport of #73882 addresses CVE-2019-18849 (cherry picked from commit b9d458d91c1d39b8b5954c84afc862b044cf84d5)