CVE-2023-4244

Local privilege escalation via nf_tables reference underflow

Published Sep 6, 2023 · Updated Jul 28, 2026

Use-after-free in Linux Kernel affected releases allows local users to gain elevated privileges through an nf_tables netlink race. During an nf_tables control-plane transaction, set-element garbage collection can decrement a reference count below zero and free an object that remains reachable. Exploitation requires local low-privileged access and winning the race; successful abuse grants elevated execution, while failed attempts can crash the system.

CVSS severity7.8
High
EPSS probability0.24%
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 Linux Kernel affected releases allows local users to gain elevated privileges through an nf_tables netlink race. During an nf_tables control-plane transaction, set-element garbage collection can decrement a reference count below zero and free an object that remains reachable. Exploitation requires local low-privileged access and winning the race; successful abuse grants elevated execution, while failed attempts can crash the system.

The record

CVE
CVE-2023-4244
Published
Sep 6, 2023
Updated
Jul 28, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 6, 2023CVE publishedPublication date reported by the CVE source.
  2. Jul 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0.0 <4.19.316
  2. Affected versionversion=4.20 <5.4.262
  3. Affected versionversion=5.11 <5.15.134
  4. Affected versionversion=5.16 <6.1.56
  5. Affected versionversion=5.5 <5.10.198
  6. Affected versionversion=6.2 <6.4.11

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=0.0 <4.19.316; version=4.20 <5.4.262; version=5.11 <5.15.134; version=5.16 <6.1.56; version=5.5 <5.10.198; version=6.2 <6.4.11

Published CVSS scores

7.8National Vulnerability DatabaseCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

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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