v9fs_wstat in hw/9pfs/9p.c in QEMU allows guest OS users to cause a denial of service (crash) because of a race condition during file renaming.
https://www.debian.org/security/2019/dsa-4454
https://usn.ubuntu.com/3923-1/
https://security-tracker.debian.org/tracker/CVE-2018-19489
https://seclists.org/bugtraq/2019/May/76
https://lists.gnu.org/archive/html/qemu-devel/2018-11/msg04489.html
https://lists.debian.org/debian-lts-announce/2019/01/msg00023.html
https://git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=1d20398694a3b67a388d955b7a945ba4aa90a8a8
https://exchange.xforce.ibmcloud.com/vulnerabilities/153326
http://www.securityfocus.com/bid/106007
http://www.openwall.com/lists/oss-security/2018/11/26/1
http://lists.opensuse.org/opensuse-security-announce/2019-03/msg00042.html