Use-after-free in Linux kernel - CVE-2026-72085
Published: August 16, 2026
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to a refcount underflow leading to use-after-free in xen-scsiback request handling when processing pvSCSI requests before command submission. A remote user can submit requests with a bad grant reference or an unknown request type to cause a denial of service.
Under panic_on_warn, triggering the refcount underflow can panic the host. The issue can also leak every command tag of a LUN session, stopping the LUN.
Affected software
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
How to mitigate CVE-2026-72085
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14
External References
- https://git.kernel.org/stable/c/1e97c404e44991fb087c38ccd7414f2d326f9b74
- https://git.kernel.org/stable/c/9c0f6894982b1f13bda220707497b25ac9c95bdb
- https://git.kernel.org/stable/c/a13b789497a7fdd27d4d63f5c69d23db706ef0fe
- https://git.kernel.org/stable/c/ca978f8a93d4d36841839bf2847d29b88c2591d6
- https://git.kernel.org/stable/c/f1516c56ac540da1769f264c3cfefe4499548a5d
- https://git.kernel.org/stable/c/fa588f28401102652068c4cc75e135507f4b5106
- https://git.kernel.org/stable/c/fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45