A flaw was found in the Linux kernel in versions before 5.9-rc6. When changing screen size, an out-of-bounds memory write can occur leading to memory corruption or a denial of service. Due to the nature of the flaw, privilege escalation cannot be fully ruled out.
https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
https://bugzilla.redhat.com/show_bug.cgi?id=1876788
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00001.html