CVE-2023-54206

Kernel crash via flower filter initialization race

Published Dec 30, 2025 · Updated Dec 30, 2025

Race condition in Linux 6.3 through 6.3.2 allows local users to crash or hang the kernel through concurrent flower filter operations. fl_change inserts a filter into the IDR before initialization finishes, allowing fl_get or deletion paths to dereference or modify inconsistent state. The race requires a local user with a user namespace that grants CAP_NET_ADMIN; successful triggering crashes the kernel or deadlocks later filter operations.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in Linux 6.3 through 6.3.2 allows local users to crash or hang the kernel through concurrent flower filter operations. fl_change inserts a filter into the IDR before initialization finishes, allowing fl_get or deletion paths to dereference or modify inconsistent state. The race requires a local user with a user namespace that grants CAP_NET_ADMIN; successful triggering crashes the kernel or deadlocks later filter operations.

The record

CVE
CVE-2023-54206
Published
Dec 30, 2025
Updated
Dec 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

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=08a0063df3aed8d76a4034279117db12dbc1050f <253a3a324e0ebc2825de76a0f5f17b8383b2023d
  2. Affected versionversion=08a0063df3aed8d76a4034279117db12dbc1050f <dd4f6bbfa646f258e5bcdfac57a5c413d687f588
  3. Affected versionversion=6.3

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=08a0063df3aed8d76a4034279117db12dbc1050f <253a3a324e0ebc2825de76a0f5f17b8383b2023d; version=08a0063df3aed8d76a4034279117db12dbc1050f <dd4f6bbfa646f258e5bcdfac57a5c413d687f588; version=6.3

Published CVSS scores

7.8LinuxCVSS: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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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