A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.
https://ubuntu.com/security/CVE-2021-3748
https://security.netapp.com/advisory/ntap-20220425-0004/
https://security.gentoo.org/glsa/202208-27
https://lists.nongnu.org/archive/html/qemu-devel/2021-09/msg00388.html
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
https://lists.debian.org/debian-lts-announce/2022/04/msg00002.html
https://github.com/qemu/qemu/commit/bedd7e93d01961fcb16a97ae45d93acf357e11f6