Use-after-free in Linux kernel - CVE-2026-46317

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU134177

Use-after-free in Linux kernel - CVE-2026-46317

Published: June 10, 2026


Vulnerability identifier: #VU134177
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-46317
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in the nested_mmus array in arm64 KVM nested virtualization when reallocating nested MMU structures while the array is being walked under mmu_lock. A local user can trigger nested vcpu initialization and concurrent MMU notifier activity to cause a denial of service.

The issue arises from a race condition between nested vcpu initialization and the MMU notifier path.


Affected software

Linux kernel
Ubuntu
linux-azure-fde-6.17 (Ubuntu package)
linux-gcp-6.17 (Ubuntu package)
linux-oracle-6.17 (Ubuntu package)
linux-azure-6.17 (Ubuntu package)
linux-oem-6.17 (Ubuntu package)
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-46317

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-azure-fde-6.17 (Ubuntu package) - update to 6.17.0-1018.18~24.04.1
linux-gcp-6.17 (Ubuntu package) - addressed in versions 6.17.0-1018.20~24.04.1, 6.17.0-1021.24~24.04.1
linux-oracle-6.17 (Ubuntu package) - addressed in versions 6.17.0-1019.19~24.04.3, 6.17.0-1019.19~24.04.3+1
linux-azure-6.17 (Ubuntu package) - update to 6.17.0-1021.21~24.04.1
linux-oem-6.17 (Ubuntu package) - update to 6.17.0-1030.30
linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

External References

Related Security Bulletins