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7.1
HIGH CVSS 3.1
CVE-2026-64284
KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.

Details
INFO

Published Date :

July 25, 2026, 10:17 a.m.

Last Modified :

Aug. 17, 2026, 5:17 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-64284 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Update Linux kernel to ensure vendor exit handlers execute correctly.
  • Apply kernel patches for KVM VMX and SVM.
  • Ensure vendor exit handlers run before userspace.
  • Flush PML buffer prior to exiting to userspace.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-64284.

URL Resource
https://git.kernel.org/stable/c/0ffedf43910e44b76c2c1db4e9fbf12b268190c1 Patch
https://git.kernel.org/stable/c/4ad73ef0e7966ecfe67de0060537b4cb14d9acd4 Patch
https://git.kernel.org/stable/c/b3436d9b9b1affe1c3191ac9831308923f5f03c3 Patch
https://git.kernel.org/stable/c/f2ca2b5326211bd38490f0497eb583721ce0bbc0 Patch
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-64284 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-64284 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-64284 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-64284 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Aug. 17, 2026

    Action Type Old Value New Value
    Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': 'b3436d9b9b1affe1c3191ac9831308923f5f03c3', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': '4ad73ef0e7966ecfe67de0060537b4cb14d9acd4', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': 'f2ca2b5326211bd38490f0497eb583721ce0bbc0', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': '0ffedf43910e44b76c2c1db4e9fbf12b268190c1', 'versionType': 'git'}], 'programFiles': ['arch/x86/kvm/svm/svm.c', 'arch/x86/kvm/vmx/vmx.c', 'arch/x86/kvm/x86.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/kvm/svm/svm.c', 'arch/x86/kvm/vmx/vmx.c', 'arch/x86/kvm/x86.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': 'b3436d9b9b1affe1c3191ac9831308923f5f03c3', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': '4ad73ef0e7966ecfe67de0060537b4cb14d9acd4', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': 'f2ca2b5326211bd38490f0497eb583721ce0bbc0', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': '0ffedf43910e44b76c2c1db4e9fbf12b268190c1', 'versionType': 'git'}], 'programFiles': ['arch/x86/kvm/svm/svm.c', 'arch/x86/kvm/vmx/vmx.c', 'arch/x86/kvm/x86.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/kvm/svm/svm.c', 'arch/x86/kvm/vmx/vmx.c', 'arch/x86/kvm/x86.c'], 'defaultStatus': 'affected'}]
  • Initial Analysis by [email protected]

    Aug. 13, 2026

    Action Type Old Value New Value
    Added CWE CWE-367
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.39 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.1.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.12 up to (excluding) 6.12.96
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/0ffedf43910e44b76c2c1db4e9fbf12b268190c1 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/4ad73ef0e7966ecfe67de0060537b4cb14d9acd4 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/b3436d9b9b1affe1c3191ac9831308923f5f03c3 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/f2ca2b5326211bd38490f0497eb583721ce0bbc0 Types: Patch
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 27, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 25, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': 'b3436d9b9b1affe1c3191ac9831308923f5f03c3', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': '4ad73ef0e7966ecfe67de0060537b4cb14d9acd4', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': 'f2ca2b5326211bd38490f0497eb583721ce0bbc0', 'versionType': 'git'}, {'status': 'affected', 'version': 'f7f39c50edb9d336274371953275e0d3503b9b75', 'lessThan': '0ffedf43910e44b76c2c1db4e9fbf12b268190c1', 'versionType': 'git'}], 'programFiles': ['arch/x86/kvm/svm/svm.c', 'arch/x86/kvm/vmx/vmx.c', 'arch/x86/kvm/x86.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.4', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['arch/x86/kvm/svm/svm.c', 'arch/x86/kvm/vmx/vmx.c', 'arch/x86/kvm/x86.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Ensure vendor's exit handler runs before fastpath userspace exits Move the handling of fastpath userspace exits into vendor code to ensure KVM runs vendor specific operations that need to run before userspace gains control of the vCPU. E.g. for VMX (and soon to be for SVM as well), KVM needs to flush the PML buffer prior to exiting to userspace, otherwise any memory written by the final KVM_RUN might never be flagged as dirty. Note, waiting to snapshot CR0 and CR3 until svm_handle_exit() is flawed in general, as that risks consuming stale state in a fastpath handler. That will be addressed in a future change.
    Added Reference https://git.kernel.org/stable/c/0ffedf43910e44b76c2c1db4e9fbf12b268190c1
    Added Reference https://git.kernel.org/stable/c/4ad73ef0e7966ecfe67de0060537b4cb14d9acd4
    Added Reference https://git.kernel.org/stable/c/b3436d9b9b1affe1c3191ac9831308923f5f03c3
    Added Reference https://git.kernel.org/stable/c/f2ca2b5326211bd38490f0497eb583721ce0bbc0
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.1
Attack Vector
Attack Complexity
Privileges Required
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Scope
Confidentiality Impact
Integrity Impact
Availability Impact