# CVE-2024-58083: KVM: Explicitly verify target vCPU is online in kvm_get_vcpu()

> A use-after-free in Linux KVM allows attackers to potentially execute code or escalate privileges by triggering a race condition during vCPU creation.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **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:** Yes
- **Published:** 6 Mar 2025
- **Updated:** 15 Oct 2026
- **Also known as:** AZL-59423, BELL-CVE-2024-58083, DEBIAN-CVE-2024-58083, GHSA-gw27-9x3h-33gj, ROOT-OS-UBUNTU-2404-CVE-2024-58083, UBUNTU-CVE-2024-58083

## What is CVE-2024-58083?

CVE-2024-58083 is a high-severity use after free vulnerability in Linux kernel, published on 6 Mar 2025. 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:

KVM: Explicitly verify target vCPU is online in kvm_get_vcpu()

Explicitly verify the target vCPU is fully online _prior_ to clamping the
index in kvm_get_vcpu().  If the index is "bad", the nospec clamping will
generate '0', i.e. KVM will return vCPU0 instead of NULL.

In practice, the bug is unlikely to cause problems, as it will only come
into play if userspace or the guest is buggy or misbehaving, e.g. KVM may
send interrupts to vCPU0 instead of dropping them on the floor.

However, returning vCPU0 when it shouldn't exist per online_vcpus is
problematic now that KVM uses an xarray for the vCPUs array, as KVM needs
to insert into the xarray before publishing the vCPU to userspace (see
commit c5b077549136 ("KVM: Convert the kvm->vcpus array to a xarray")),
i.e. before vCPU creation is guaranteed to succeed.

As a result, incorrectly providing access to vCPU0 will trigger a
use-after-free if vCPU0 is dereferenced and kvm_vm_ioctl_create_vcpu()
bails out of vCPU creation due to an error and frees vCPU0.  Commit
afb2acb2e3a3 ("KVM: Fix vcpu_array[0] races") papered over that issue, but
in doing so introduced an unsolvable teardown conundrum.  Preventing
accesses to vCPU0 before it's fully online will allow reverting commit
afb2acb2e3a3, without re-introducing the vcpu_array[0] UAF race.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2024-58083?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-58083?

Apply the vendor's patch.

## Is CVE-2024-58083 being exploited?

There is no known exploitation of CVE-2024-58083 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-58083 and fix it if it is affected.

What it is: CVE-2024-58083 is a high-severity use after free vulnerability in Linux kernel, published on 6 Mar 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-58083 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-58083/ (Markdown: https://insights.sbomify.com/CVE-2024-58083/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-58083
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-58083
- OSV: https://osv.dev/vulnerability/CVE-2024-58083

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-58083/
Summaries are generated and may contain mistakes; the official description above is the record.