CVE-2021-46967

Kernel panic via missing doorbell mapping flags

Published Feb 27, 2024 · Updated Aug 5, 2026

Denial of service in affected Linux versions allows local users to panic the kernel through a vhost-vdpa IOTLB doorbell mapping. vhost_vdpa_mmap assigns mapping operations without marking the register-backed VMA as VM_IO, VM_PFNMAP, VM_DONTEXPAND, and VM_DONTDUMP, so memory-management code can treat the mapping as if it had backing page structures. Exploitation requires local access to a configured vhost-vdpa device and an attempted IOTLB mapping; the documented consequence is a host-kernel panic.

CVSS severity7.8
High
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in affected Linux versions allows local users to panic the kernel through a vhost-vdpa IOTLB doorbell mapping. vhost_vdpa_mmap assigns mapping operations without marking the register-backed VMA as VM_IO, VM_PFNMAP, VM_DONTEXPAND, and VM_DONTDUMP, so memory-management code can treat the mapping as if it had backing page structures. Exploitation requires local access to a configured vhost-vdpa device and an attempted IOTLB mapping; the documented consequence is a host-kernel panic.

The record

CVE
CVE-2021-46967
Published
Feb 27, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 27, 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=5.8
  2. Affected versionversion=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <3a3e0fad16d40a2aa68ddf7eea4acdf48b22dd44
  3. Affected versionversion=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <3b8b6399666a29daa30b0bb3f5c9e3fc81c5a6a6
  4. Affected versionversion=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <93dbbf20e3ffad14f04227a0b7105f6e6f0387ce
  5. Affected versionversion=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <940230a5c31e2714722aee04c521a21f484b4df7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.8; version=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <3a3e0fad16d40a2aa68ddf7eea4acdf48b22dd44; version=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <3b8b6399666a29daa30b0bb3f5c9e3fc81c5a6a6; version=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <93dbbf20e3ffad14f04227a0b7105f6e6f0387ce; version=ddd89d0a059d8e9740c75a97e0efe9bf07ee51f9 <940230a5c31e2714722aee04c521a21f484b4df7

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.

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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

T1499.004Application or System Exploitation

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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