CVE-2021-47112

Kernel memory corruption via stale PV mappings

Published Mar 15, 2024 · Updated Aug 5, 2026

Improper KVM state cleanup in the Linux kernel allows attackers to corrupt kernel memory when an affected guest resumes from hibernation. The boot CPU leaves Async PF, PV EOI, and steal-time shared-memory features active, so the hypervisor can write through stale mappings after the prior kernel image is restored. Reachability requires an x86 KVM guest using these PV features and a hibernation-resume cycle; the resulting writes can corrupt memory reassigned by the restored kernel.

CVSS severity7.8
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper KVM state cleanup in the Linux kernel allows attackers to corrupt kernel memory when an affected guest resumes from hibernation. The boot CPU leaves Async PF, PV EOI, and steal-time shared-memory features active, so the hypervisor can write through stale mappings after the prior kernel image is restored. Reachability requires an x86 KVM guest using these PV features and a hibernation-resume cycle; the resulting writes can corrupt memory reassigned by the restored kernel.

The record

CVE
CVE-2021-47112
Published
Mar 15, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 15, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.6.38
  2. Affected versionversion=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <38b858da1c58ad46519a257764e059e663b59ff2
  3. Affected versionversion=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <7620a669111b52f224d006dea9e1e688e2d62c54
  4. Affected versionversion=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <8b79feffeca28c5459458fe78676b081e87c93a4
  5. Affected versionversion=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <d1629b5b925de9b27979e929dae7fcb766daf6b6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.38; version=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <38b858da1c58ad46519a257764e059e663b59ff2; version=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <7620a669111b52f224d006dea9e1e688e2d62c54; version=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <8b79feffeca28c5459458fe78676b081e87c93a4; version=fd10cde9294f73eeccbc16f3fec1ae6cde7b800c <d1629b5b925de9b27979e929dae7fcb766daf6b6

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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