# CVE-2026-72278: KVM: arm64: nv: Re-translate VNCR before injecting abort

> A flaw in Linux KVM arm64 nested virtualization could cause incorrect memory translation handling, potentially leading to denial of service.

- **Severity:** Critical 9.3 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **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:** BELL-CVE-2026-72278, DEBIAN-CVE-2026-72278, GHSA-8rrh-94xj-vxx2, UBUNTU-CVE-2026-72278

## What is CVE-2026-72278?

CVE-2026-72278 is a critical 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: arm64: nv: Re-translate VNCR before injecting abort

KVM faults in the VNCR page with FOLL_WRITE whenever the guest aborts
for a write, similar to how a regular stage-2 mapping is handled. It is
entirely possible that the guest reads from the VNCR before writing to
it, in which case the PFN could only be read-only.

Invalidate the VNCR TLB and re-fetch the translation upon taking a VNCR
abort, allowing the host mapping to be faulted in for write the second
time around. Interestingly enough, this also satisfies the ordering
requirements of FEAT_ETS2/3 between descriptor updates and MMU faults.

## Which versions are affected by CVE-2026-72278?


## How do I fix CVE-2026-72278?

Apply the vendor's patch.

## Is CVE-2026-72278 being exploited?

There is no known exploitation of CVE-2026-72278 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-72278 and fix it if it is affected.

What it is: CVE-2026-72278 is a critical 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-2026-72278 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-2026-72278/ (Markdown: https://insights.sbomify.com/CVE-2026-72278/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-72278
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-72278
- OSV: https://osv.dev/vulnerability/CVE-2026-72278

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-72278/
Summaries are generated and may contain mistakes; the official description above is the record.