CVE-2021-47093

Kernel memory leak via failed device registration

Published Mar 4, 2024 · Updated May 11, 2026

Memory leak in the Linux kernel 5.9 through 5.16-rc6 allows local users to consume kernel memory after failed device registration. The intel_pmc_core initialization error path returns after platform-device registration fails without calling platform_device_put(), leaving the device structure and resources such as its name allocated. Reachability requires local low-privileged access and a registration failure during module initialization; each failure leaves memory unavailable, with no reported confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux kernel 5.9 through 5.16-rc6 allows local users to consume kernel memory after failed device registration. The intel_pmc_core initialization error path returns after platform-device registration fails without calling platform_device_put(), leaving the device structure and resources such as its name allocated. Reachability requires local low-privileged access and a registration failure during module initialization; each failure leaves memory unavailable, with no reported confidentiality or integrity impact.

The record

CVE
CVE-2021-47093
Published
Mar 4, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 4, 2024CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=5.9
  2. Affected versionversion=938835aa903ae19ad62805134f79bbcf20fc3bea <26a8b09437804fabfb1db080d676b96c0de68e7c
  3. Affected versionversion=938835aa903ae19ad62805134f79bbcf20fc3bea <7a37f2e370699e2feca3dca6c8178c71ceee7e8a
  4. Affected versionversion=938835aa903ae19ad62805134f79bbcf20fc3bea <9ca1324755f1f8629a370af5cc315b175331f5d1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.9; version=938835aa903ae19ad62805134f79bbcf20fc3bea <26a8b09437804fabfb1db080d676b96c0de68e7c; version=938835aa903ae19ad62805134f79bbcf20fc3bea <7a37f2e370699e2feca3dca6c8178c71ceee7e8a; version=938835aa903ae19ad62805134f79bbcf20fc3bea <9ca1324755f1f8629a370af5cc315b175331f5d1

Published CVSS scores

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

CWE-401Missing Release of Memory after Effective Lifetime
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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