NULL pointer dereference in Linux kernel - CVE-2026-99176
Published: October 29, 2026
Vulnerability identifier: #VU158403
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-2026-99176
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service through a kernel NULL pointer dereference.
The vulnerability exists due to a failure to restore the root MMU context in the Linux kernel's KVM nested VMX implementation when loading L2 state fails during RSM emulation or KVM_SET_NESTED_STATE handling. A local user can trigger this failure and subsequently free the nested virtualization state, leaving the vCPU using a nested MMU while running L1, to cause a NULL pointer dereference when KVM accesses the L1-to-L2 EPT pointer.
Affected software
Linux kernel
Debian Linux
linux (Debian package)
Debian Linux
linux (Debian package)
How to mitigate CVE-2026-99176
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3
linux (Debian package) - update to 6.12.115-2
linux (Debian package) - update to 6.12.115-2