CVE-2020-8834

Host kernel panic via guest-state stack corruption

Published Apr 9, 2020 · Updated Sep 16, 2024

Stack corruption in Linux kernel KVM 4.8 through 4.17 allows guest OS users with kernel-code execution to panic the Power8 host. During hypercalls in Transactional Memory suspend mode, kvmppc_hv_entry and the kvmppc_save_tm and kvmppc_restore_tm routines reuse HSTATE_HOST_R1 for incompatible host and guest r1 state, corrupting the saved stack-frame address. Exploitation requires kernel-code execution inside a KVM guest on a Power8 host, and the documented consequence is a host crash rather than data access or modification.

CVSS severity6.5
Medium
EPSS probability0.35%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack corruption in Linux kernel KVM 4.8 through 4.17 allows guest OS users with kernel-code execution to panic the Power8 host. During hypercalls in Transactional Memory suspend mode, kvmppc_hv_entry and the kvmppc_save_tm and kvmppc_restore_tm routines reuse HSTATE_HOST_R1 for incompatible host and guest r1 state, corrupting the saved stack-frame address. Exploitation requires kernel-code execution inside a KVM guest on a Power8 host, and the documented consequence is a host crash rather than data access or modification.

The record

CVE
CVE-2020-8834
Published
Apr 9, 2020
Updated
Sep 16, 2024
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-362, CWE-368, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 9, 2020CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record 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=4.8 <unspecified
  2. Affected versionversion=unspecified <4.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.8 <unspecified; version=unspecified <4.18

Published CVSS scores

6.5Canonical Ltd.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
4.9NIST NVDAV:L/AC:L/Au:N/C:N/I:N/A:C

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CWE-368Context Switching Race Condition
T1499Endpoint Denial of Service

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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