CVE-2026-31558 LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
A missing bounds check in the Linux kernel's KVM module allows out-of-bounds memory access, potentially leading to crashes or code execution.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31558?
CVE-2026-31558 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Apr 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
kvm_get_vcpu_by_cpuid() takes a cpuid parameter whose type is int, so cpuid can be negative. Let kvm_get_vcpu_by_cpuid() return NULL for this case so as to make it more robust.
This fix an out-of-bounds access to kvm_arch::phyid_map::phys_map[].
Weakness: CWE-125
Which versions are affected by CVE-2026-31558?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31558?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-31558 being exploited?
There is no known exploitation of CVE-2026-31558 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-31558, DEBIAN-CVE-2026-31558, GHSA-75vg-fcxx-gf7x, UBUNTU-CVE-2026-31558.