AUGUST 4, 2026
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Case File

CVE-2021-29657

HIGH · CVSS 7.4 EPSS 0.41% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-07-22 · Last synced 2026-08-04

CyberRota Analysis

AI analysis pending.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

External Security References

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CVE
CVE-2021-29657
Severity
HIGH
CVSS
7.4
EPSS
0.41%
Linux

Original NVD Description

arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.