CVE-2021-47184

Kernel crash via unsynchronized i40e VSI teardown

Published Apr 10, 2024 · Updated Aug 5, 2026

NULL pointer dereference in the Linux kernel's i40e driver allows local users to crash the kernel during concurrent VSI teardown. The filter-sync worker can update a VSI filter list after teardown has removed the VSI, dereferencing invalid state and producing a kernel oops. Triggering requires local low-privileged access and an active i40e VSI undergoing filter synchronization while it is removed.

CVSS severity8.8
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

NULL pointer dereference in the Linux kernel's i40e driver allows local users to crash the kernel during concurrent VSI teardown. The filter-sync worker can update a VSI filter list after teardown has removed the VSI, dereferencing invalid state and producing a kernel oops. Triggering requires local low-privileged access and an active i40e VSI undergoing filter synchronization while it is removed.

The record

CVE
CVE-2021-47184
Published
Apr 10, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 10, 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=3.12
  2. Affected versionversion=41c445ff0f482bb6e6b72dcee9e598e20575f743 <37d9e304acd903a445df8208b8a13d707902dea6
  3. Affected versionversion=41c445ff0f482bb6e6b72dcee9e598e20575f743 <78f2a9e831f9610e3655a0be5e675e1aa2472089
  4. Affected versionversion=41c445ff0f482bb6e6b72dcee9e598e20575f743 <87c421ab4a43433cb009fea44bbbc77f46913e1d
  5. Affected versionversion=41c445ff0f482bb6e6b72dcee9e598e20575f743 <c30162da91327e4cdf7cd03079f096bb3654738c
  6. Affected versionversion=41c445ff0f482bb6e6b72dcee9e598e20575f743 <e91e8427a1e1633a0261e3bb0201c836ac5b3890
  7. Affected versionversion=41c445ff0f482bb6e6b72dcee9e598e20575f743 <f866513ead4370402428ef724b03c3312295c178

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.12; version=41c445ff0f482bb6e6b72dcee9e598e20575f743 <37d9e304acd903a445df8208b8a13d707902dea6; version=41c445ff0f482bb6e6b72dcee9e598e20575f743 <78f2a9e831f9610e3655a0be5e675e1aa2472089; version=41c445ff0f482bb6e6b72dcee9e598e20575f743 <87c421ab4a43433cb009fea44bbbc77f46913e1d; version=41c445ff0f482bb6e6b72dcee9e598e20575f743 <c30162da91327e4cdf7cd03079f096bb3654738c; version=41c445ff0f482bb6e6b72dcee9e598e20575f743 <e91e8427a1e1633a0261e3bb0201c836ac5b3890; version=41c445ff0f482bb6e6b72dcee9e598e20575f743 <f866513ead4370402428ef724b03c3312295c178

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
8.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/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

CWE-476NULL Pointer Dereference
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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