It was discovered that VCFtools improperly handled certain input. If a user were tricked into opening a crafted input file, VCFtools could be made to crash or possibly cause other unspecified impact. (CVE-2018-11099, CVE-2018-11129, CVE-2018-11130)
It was discovered that VCFtools improperly handled memory allocation/deallocation, resulting in a use-after-free vulnerability. If a victim were tricked into opening a specially crafted VCF File, an attacker could cause VCFtools to leak sensitive information or possibly execute arbitrary code. (CVE-2019-1010127)