CVE-2023-6040

Local denial of service via unchecked table family

Published Jan 12, 2024 · Updated Jun 17, 2025

Out-of-bounds read in Linux netfilter before 5.18-rc1 allows local users to crash the host via a crafted table family value. Missing family validation lets xt_find_target index xt outside its bounds and lets nf_logger_find_get index past the global loggers array. The path requires access to an unprivileged user namespace, and exploitation can interrupt the entire host.

CVSS severity7.8
High
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Linux netfilter before 5.18-rc1 allows local users to crash the host via a crafted table family value. Missing family validation lets xt_find_target index xt outside its bounds and lets nf_logger_find_get index past the global loggers array. The path requires access to an unprivileged user namespace, and exploitation can interrupt the entire host.

The record

CVE
CVE-2023-6040
Published
Jan 12, 2024
Updated
Jun 17, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1068, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 12, 2024CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 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=0 <5.18-rc1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0 <5.18-rc1

Published CVSS scores

4.4SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
7.8Canonical Ltd.CVSS: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.

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1068Exploitation for Privilege Escalation
T1499.004Application or System Exploitation

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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