CVE-2021-47388

Kernel memory corruption via stale receive header

Published May 21, 2024 · Updated Aug 5, 2026

Use-after-free in the Linux mac80211 receive path allows adjacent attackers to corrupt kernel memory via encrypted Wi-Fi frames. The receive path retains the hdr pointer across frame-buffer operations that can reallocate storage, then uses that stale pointer while copying a CCMP or GCMP packet number for fragment checks. Reachability requires an adjacent peer able to supply valid encrypted Wi-Fi frames; the resulting memory corruption can crash the kernel or compromise kernel data and execution.

CVSS severity8.8
High
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux mac80211 receive path allows adjacent attackers to corrupt kernel memory via encrypted Wi-Fi frames. The receive path retains the hdr pointer across frame-buffer operations that can reallocate storage, then uses that stale pointer while copying a CCMP or GCMP packet number for fragment checks. Reachability requires an adjacent peer able to supply valid encrypted Wi-Fi frames; the resulting memory corruption can crash the kernel or compromise kernel data and execution.

The record

CVE
CVE-2021-47388
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 21, 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=0f716b48ed25503e6961f4b5b40ece36f7e4ed26 <3d5d629c99c468458022e9b381789de3595bf4dd
  2. Affected versionversion=1f0bf30c01d3f4de7d6c5e27b102a808c5646676
  3. Affected versionversion=4.14.235 <4.14.249
  4. Affected versionversion=4.19.193 <4.19.209
  5. Affected versionversion=4.4.271 <4.4.286
  6. Affected versionversion=4.9.271 <4.9.285
  7. Affected versionversion=5.10.42 <5.10.71
  8. Affected versionversion=5.12.9 <5.13
  9. Affected versionversion=5.13
  10. Affected versionversion=5.4.124 <5.4.151
  11. Affected versionversion=608b0a2ae928a74a2f89e02227339dd79cdb63cf <447d001b875d0e7f211c4ba004916028da994258
  12. Affected versionversion=a9b57952fed41556c950a92123086724eaf11919 <f556e1d6fb9f2923a9a36f3df638c7d79ba09dbb
  13. Affected versionversion=bf30ca922a0c0176007e074b0acc77ed345e9990 <27d3eb5616ee2c0a3b30c3fa34813368ed1f3dc9
  14. Affected versionversion=bf30ca922a0c0176007e074b0acc77ed345e9990 <94513069eb549737bcfc3d988d6ed4da948a2de8
  15. Affected versionversion=c8b3a6150dc8ac78d5fdd5fbdfc4806249ef8b2c <50149e0866a82cef33e680ee68dc380a5bc75d32
  16. Affected versionversion=d0f613fe6de344dc17ba04a88921a2094c13d3fa <31de381aef0ab1b342f62485118dc8a19363dc78
  17. Affected versionversion=e64ea0597050157f926ac2ba9b478a44ee5be945 <57de2dcb18742dc2860861c9f496da7d42b67da0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0f716b48ed25503e6961f4b5b40ece36f7e4ed26 <3d5d629c99c468458022e9b381789de3595bf4dd; version=1f0bf30c01d3f4de7d6c5e27b102a808c5646676; version=4.14.235 <4.14.249; version=4.19.193 <4.19.209; version=4.4.271 <4.4.286; version=4.9.271 <4.9.285; version=5.10.42 <5.10.71; version=5.12.9 <5.13; version=5.13; version=5.4.124 <5.4.151; version=608b0a2ae928a74a2f89e02227339dd79cdb63cf <447d001b875d0e7f211c4ba004916028da994258; version=a9b57952fed41556c950a92123086724eaf11919 <f556e1d6fb9f2923a9a36f3df638c7d79ba09dbb; version=bf30ca922a0c0176007e074b0acc77ed345e9990 <27d3eb5616ee2c0a3b30c3fa34813368ed1f3dc9; version=bf30ca922a0c0176007e074b0acc77ed345e9990 <94513069eb549737bcfc3d988d6ed4da948a2de8; version=c8b3a6150dc8ac78d5fdd5fbdfc4806249ef8b2c <50149e0866a82cef33e680ee68dc380a5bc75d32; version=d0f613fe6de344dc17ba04a88921a2094c13d3fa <31de381aef0ab1b342f62485118dc8a19363dc78; version=e64ea0597050157f926ac2ba9b478a44ee5be945 <57de2dcb18742dc2860861c9f496da7d42b67da0

Published CVSS scores

8.8Linux Kernel CNACVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
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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