ClamAV version version 0.99.3 contains a Out of bounds heap memory read vulnerability in XAR parser, function xar_hash_check() that can result in Leaking of memory, may help in developing exploit chains.. This attack appear to be exploitable via The victim must scan a crafted XAR file. This vulnerability appears to have been fixed in after commit d96a6b8bcc7439fa7e3876207aa0a8e79c8451b6.
https://usn.ubuntu.com/3592-2/
https://usn.ubuntu.com/3592-1/
https://security.gentoo.org/glsa/201804-16
https://lists.debian.org/debian-lts-announce/2018/03/msg00011.html
https://github.com/Cisco-Talos/clamav-devel/commit/d96a6b8bcc7439fa7e3876207aa0a8e79c8451b6