SB2026102210 - Use-after-free in Linux kernel arm64 kvm

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-98440)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 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]

The vulnerability allows a local user to potentially cause a denial of service through access to freed kernel memory.

The vulnerability exists due to use-after-free in the Linux kernel arm64 KVM nested virtualization subsystem when kvm_arch_flush_shadow_all() frees shadow stage-2 MMU containers that other parts of the system may still reference. A local user can potentially trigger access to these freed structures during shadow mapping operations to cause a kernel crash.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/22e82acec93a681071ed36f70eabe2d0c4e0bebd
• https://git.kernel.org/stable/c/5bf1c9175e657b3c2dc1cf77403031ac7aadcf66
• https://git.kernel.org/stable/c/876049f026b4dfaca0cc78ec81be0e639ca8525d
• https://git.kernel.org/stable/c/e5843f4effaa2ffac3e789ecd4456403564961d4