Use-after-free in Linux kernel - CVE-2026-72085

 

Use-after-free in Linux kernel - CVE-2026-72085

Published: August 16, 2026


Vulnerability identifier: #VU143505
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-72085
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability: No public exploit available

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

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)

How to mitigate CVE-2026-72085

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
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

Related Security Bulletins