CVE-2023-4004Public exploit

Local privilege escalation via missing end-key validation

Published Jul 31, 2023 · Updated Nov 8, 2025

Use-after-free in Linux kernel netfilter on Red Hat Enterprise Linux allows local users to crash the system or escalate privileges. nft_pipapo_remove unconditionally reads a nonexistent end-key extension for singleton set elements, so it can remove the wrong entry and leave a dangling reference. Local users able to create the required nftables set, including through enabled unprivileged user namespaces, can gain root privileges; failed attempts can crash the host.

CVSS severity7.8
High
EPSS probability0.94%
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 netfilter on Red Hat Enterprise Linux allows local users to crash the system or escalate privileges. nft_pipapo_remove unconditionally reads a nonexistent end-key extension for singleton set elements, so it can remove the wrong entry and leave a dangling reference. Local users able to create the required nftables set, including through enabled unprivileged user namespaces, can gain root privileges; failed attempts can crash the host.

The record

CVE
CVE-2023-4004
Published
Jul 31, 2023
Updated
Nov 8, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 31, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 8, 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?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Red Hat · Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update SupportAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 9.0 Extended Update SupportAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 8.2 Advanced Update SupportAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 8.2 Telecommunications Update ServiceAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 8.2 Update Services for SAP SolutionsAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 8.4 Telecommunications Update ServiceAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 8.6 Extended Update SupportAffected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 8.4 Update Services for SAP SolutionsAffected versions are unavailable in this record.
Red Hat · Red Hat Virtualization 4 for Red Hat Enterprise Linux 8Affected versions are unavailable in this record.

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Red HatCVSS: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 exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

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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