CVE-2021-47494

Local denial of service via registration-list corruption

Published May 22, 2024 · Updated Aug 5, 2026

Improper locking in the Linux kernel cfg80211 subsystem allows local users to trigger a kernel crash through management-registration list corruption. cfg80211_mgmt_registrations_update() iterates per-wdev registration lists without holding every required spinlock, allowing concurrent changes to corrupt the lists. Exploitation requires local low-privileged access, and published assessments report no confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in the Linux kernel cfg80211 subsystem allows local users to trigger a kernel crash through management-registration list corruption. cfg80211_mgmt_registrations_update() iterates per-wdev registration lists without holding every required spinlock, allowing concurrent changes to corrupt the lists. Exploitation requires local low-privileged access, and published assessments report no confidentiality or integrity impact.

The record

CVE
CVE-2021-47494
Published
May 22, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-667, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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=6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d <09b1d5dc6ce1c9151777f6c4e128a59457704c97
  3. Affected versionversion=6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d <3c897f39b71fe68f90599f6a45b5f7bf5618420e
  4. Affected versionversion=6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d <4c22227e39c7a0b4dab55617ee8d34d171fab8d4

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.8; version=6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d <09b1d5dc6ce1c9151777f6c4e128a59457704c97; version=6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d <3c897f39b71fe68f90599f6a45b5f7bf5618420e; version=6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d <4c22227e39c7a0b4dab55617ee8d34d171fab8d4

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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

CWE-667Improper Locking
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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