SB20260529172 - Improper Check for Unusual or Exceptional Conditions in Linux kernel x86 kvm

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Check for Unusual or Exceptional Conditions (CVE-ID: CVE-2026-46131)

CWE-ID: CWE-754 - Improper Check for Unusual or Exceptional Conditions

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

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

The vulnerability exists due to improper check of nested EPT/NPT state in KVM x86 slow flush hypercalls when handling hypercalls from a nested guest. A local user can trigger the affected hypercall path to cause a denial of service.

Exploitation requires a nested virtualization scenario in which an L2 guest is running.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/45fc766bc756ff1d66f8ca026a9c4f7f764adfae
• https://git.kernel.org/stable/c/464af6fc2b1dcc74005b7f58ee3812b17777efee
• https://git.kernel.org/stable/c/4c7f8436b19a2a3acc0cb6b6e3becd6796ae5c57
• https://git.kernel.org/stable/c/971f17f5d91045404e3914029ea57c3da90179a4
• https://git.kernel.org/stable/c/d6f4e217d663ede5becc2fd6cb612c749677387b