A race condition flaw was found in the 9pfs server implementation of QEMU up to and including 5.2.0. This flaw allows a malicious 9p client to cause a use-after-free error, potentially escalating their privileges on the system. The highest threat from this vulnerability is to confidentiality, integrity as well as system availability.
https://www.zerodayinitiative.com/advisories/ZDI-21-159/
https://security.netapp.com/advisory/ntap-20210720-0009/
https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html
https://lists.debian.org/debian-lts-announce/2021/02/msg00024.html