# CVE-2026-98928: KVM: arm64: Derive GUEST_HAS_SVE from the SVE feature bit at EL2


- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 23 Oct 2026
- **Updated:** 23 Oct 2026
- **Also known as:** BELL-CVE-2026-98928, DEBIAN-CVE-2026-98928, GHSA-vj8p-cgf2-cww7, UBUNTU-CVE-2026-98928

## What is CVE-2026-98928?

CVE-2026-98928 is a vulnerability in Linux, published on 23 Oct 2026. 

### Official description

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Derive GUEST_HAS_SVE from the SVE feature bit at EL2

pkvm_init_features_from_host() takes KVM_ARCH_FLAG_GUEST_HAS_SVE and
KVM_ARM_VCPU_SVE from the host separately, but pkvm_vcpu_init_sve()
tests the bit while vcpu_has_sve() reads the flag. A host that sets the
flag without the bit gets a vCPU with a NULL sve_state that the world
switch loads the guest's SVE state from.

Derive the flag from the bit, and drop the protected path's copy of the
host's flag, which is dead code since protected VMs are not allowed SVE.

## Which versions are affected by CVE-2026-98928?


## How do I fix CVE-2026-98928?

Upgrade to a fixed version.

## Is CVE-2026-98928 being exploited?

There is no known exploitation of CVE-2026-98928 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-98928 and fix it if it is affected.

What it is: CVE-2026-98928 is a vulnerability in Linux, published on 23 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-98928 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-2026-98928/ (Markdown: https://insights.sbomify.com/CVE-2026-98928/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-98928
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-98928
- OSV: https://osv.dev/vulnerability/CVE-2026-98928

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-98928/
Summaries are generated and may contain mistakes; the official description above is the record.