CVE-2023-54299

Kernel crash via unchecked Alt Mode partner

Published Dec 30, 2025 · Updated Dec 30, 2025

NULL pointer dereference in affected Linux kernels allows physically proximate attackers to crash the kernel through a USB Type-C hub. The typec_altmode_attention() path sends an Attention event without confirming that a data-role swap left an Alt Mode partner, then dereferences the missing partner's typec_altmode and operations pointers. Triggering requires USB-C DisplayPort Alt Mode and a hub that swaps roles, unregisters alternate modes, and keeps sending Attention messages; systems lacking that capability are unaffected.

CVSS severity5.5
Medium
EPSS probability0.20%
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 affected Linux kernels allows physically proximate attackers to crash the kernel through a USB Type-C hub. The typec_altmode_attention() path sends an Attention event without confirming that a data-role swap left an Alt Mode partner, then dereferences the missing partner's typec_altmode and operations pointers. Triggering requires USB-C DisplayPort Alt Mode and a hub that swaps roles, unregisters alternate modes, and keeps sending Attention messages; systems lacking that capability are unaffected.

The record

CVE
CVE-2023-54299
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 30, 2025Record 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=4.19
  2. Affected versionversion=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <0ad6bad31da692f8d7acacab07eabe7586239ae0
  3. Affected versionversion=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <0d3b5fe47938e9c451466845304a2bd74e967a80
  4. Affected versionversion=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <1101867a1711c27d8bbe0e83136bec47f8c1ca2a
  5. Affected versionversion=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <38e1f2ee82bacbbfded8f1c06794a443d038d054
  6. Affected versionversion=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <5f71716772b88cbe0e1788f6a38d7871aff2120b
  7. Affected versionversion=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <d49547950bf7f3480d6ca05fe055978e5f0d9e5b
  8. Affected versionversion=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <f23643306430f86e2f413ee2b986e0773e79da31

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4.19; version=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <0ad6bad31da692f8d7acacab07eabe7586239ae0; version=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <0d3b5fe47938e9c451466845304a2bd74e967a80; version=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <1101867a1711c27d8bbe0e83136bec47f8c1ca2a; version=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <38e1f2ee82bacbbfded8f1c06794a443d038d054; version=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <5f71716772b88cbe0e1788f6a38d7871aff2120b; version=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <d49547950bf7f3480d6ca05fe055978e5f0d9e5b; version=8a37d87d72f0c69f837229c04d2fcd7117ea57e7 <f23643306430f86e2f413ee2b986e0773e79da31

Published CVSS scores

5.5Red HatCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

See the directory against your own environment.

Your stack

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