CVE-2021-47031Network attack vector

Kernel memory consumption via unfreed coredump packets

Published Feb 28, 2024 · Updated May 11, 2026

Memory leak in the mt7921 wireless driver in Linux 5.12 through 5.12.3 allows remote authenticated users to reduce availability. The mt7921_coredump_work routine can skip a coredump SKB that cannot fit in its fixed buffer without releasing the discarded packet. Exposure requires the mt7921 driver and a firmware coredump containing an over-capacity packet; public records do not document how a remote user forces that state.

CVSS severity4.3
Medium
EPSS probability0.61%
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 mt7921 wireless driver in Linux 5.12 through 5.12.3 allows remote authenticated users to reduce availability. The mt7921_coredump_work routine can skip a coredump SKB that cannot fit in its fixed buffer without releasing the discarded packet. Exposure requires the mt7921 driver and a firmware coredump containing an over-capacity packet; public records do not document how a remote user forces that state.

The record

CVE
CVE-2021-47031
Published
Feb 28, 2024
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-401
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Feb 28, 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=1c099ab44727c8e42fe4de4d91b53cec3ef02860 <4811226374453607175ea057777faa7e7f752204
  2. Affected versionversion=1c099ab44727c8e42fe4de4d91b53cec3ef02860 <782b3e86ea970e899f8e723db9f64708a15ca30e
  3. Affected versionversion=5.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1c099ab44727c8e42fe4de4d91b53cec3ef02860 <4811226374453607175ea057777faa7e7f752204; version=1c099ab44727c8e42fe4de4d91b53cec3ef02860 <782b3e86ea970e899f8e723db9f64708a15ca30e; version=5.12

Published CVSS scores

4.3CISA-ADPCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime

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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