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Researcher claims KVM guest-to-host escape; Vercel confirms

1 source · 2 articlesFirst reported Updated ()3 · 1 read
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Merged summary · grok-4.7 · rewritten as coverage arrivesSummaries by Vani AI

Paulos Yibelo says a Vercel bounty found a KVM guest-to-host root escape; Vercel confirmed a zero-day, with no public CVE or patch.

Security researcher Paulos Yibelo says work through Vercel’s bug bounty uncovered a full guest-to-host root escape in Linux KVM, the hypervisor behind Firecracker MicroVMs. Vercel CEO Guillermo Rauch said the company confirmed a KVM zero-day affecting its Sandbox product, which runs AI-agent workloads in AWS-originated Firecracker MicroVMs on KVM. The two accounts differ slightly: one describes a bounty submission that uncovered the flaw, while the other says Yibelo won the bounty; both say Vercel confirmed the issue. No CVE, patch, proof-of-concept, exploit details, or mailing-list discussion is public, and exploitation has not been reported. KVM also underpins clouds and platforms from AWS, Google, Nutanix, HPE, and Proxmox. The Register notes Januscape as another serious KVM bug found this year.

Key facts
  • Paulos Yibelo says a Vercel bug-bounty submission uncovered a full Linux KVM guest-to-host root escape.
  • Vercel CEO Guillermo Rauch said the company confirmed a KVM zero-day affecting Vercel Sandbox.
  • Vercel Sandbox runs AI-agent workloads in AWS-originated Firecracker MicroVMs, which rely on Linux KVM.
  • No CVE, patch, proof-of-concept, exploit details, or related mailing-list discussion is public, and exploitation has not been reported.
  • KVM also underpins platforms from AWS, Google, Nutanix, HPE, and Proxmox.
  • The Register notes Januscape as an earlier serious KVM bug found this year.
  • Sources differ slightly on the bounty: one says a submission uncovered the flaw; the other says Yibelo won the bounty.
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Vendors
AWSGoogleVercel
Products
Linux KVMFirecrackerVercel Sandbox
Organizations
VercelNutanixHPEProxmoxAWSGoogle

Coverage

oldest first · one row per article · UTC
  1. · 24d ago The Register · SecurityFirst report

    Security researcher claims to they found KVM guest-host escape flaw

    Researcher claims a KVM guest-to-host escape zero-day; Vercel confirmed it, but no details are public.

  2. · 24d ago The Register · Security

    Security researcher claims they found KVM guest-host escape flaw

    Paulos Yibelo claims a KVM guest-to-host root escape zero-day found via Vercel’s Firecracker sandbox bounty.