# CVE-2026-72285: KVM: TDX: Reject concurrent change to CPUID entry count

> A race condition in Linux KVM TDX allows attackers to trigger out-of-bounds memory access, potentially leading to code execution or privilege escalation.

- **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:** 15 Aug 2026
- **Updated:** 17 Aug 2026
- **Also known as:** DEBIAN-CVE-2026-72285, GHSA-725c-hm4j-27fv, UBUNTU-CVE-2026-72285

## What is CVE-2026-72285?

CVE-2026-72285 is a high-severity vulnerability in Linux, published on 15 Aug 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:

KVM: TDX: Reject concurrent change to CPUID entry count

Reject KVM_TDX_INIT_VM if userspace changes cpuid.nent between the
initial read and the subsequent copy of the initialization data.

tdx_td_init() first reads user_data->cpuid.nent to size the flexible
kvm_tdx_init_vm copy.  The copied structure also contains cpuid.nent,
and that field can differ from the value used to size the allocation if
userspace modifies the input concurrently.  setup_tdparams_cpuids() later
passes init_vm->cpuid.nent to kvm_find_cpuid_entry2(), which uses it as
the array bound for the copied entries.

Require the copied count to match the value used to size the allocation
so that CPUID parsing cannot access beyond the entries actually copied.

## Which versions are affected by CVE-2026-72285?


## How do I fix CVE-2026-72285?

Apply the vendor's patch.

## Is CVE-2026-72285 being exploited?

There is no known exploitation of CVE-2026-72285 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72285 and fix it if it is affected.

What it is: CVE-2026-72285 is a high-severity vulnerability in Linux, published on 15 Aug 2026. 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-2026-72285 in the wild and no public exploit code.

Affected product: Linux. 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-2026-72285/ (Markdown: https://insights.sbomify.com/CVE-2026-72285/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72285
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72285
- OSV: https://osv.dev/vulnerability/CVE-2026-72285

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72285/
Summaries are generated and may contain mistakes; the official description above is the record.