CVE-2023-6622

Kernel crash via unchecked dynset expression index

Published Dec 8, 2023 · Updated Nov 6, 2025

NULL pointer dereference in nf_tables in Red Hat Enterprise Linux 8 and 9 allows attackers to crash the kernel through a dynset request. nft_dynset_init compares a crafted expression against an indexed set expression without first ensuring the index is below the declared expression count, so an extra expression dereferences a NULL slot. Exploitation requires local access plus CAP_NET_ADMIN; successful triggering interrupts the host by crashing the operating-system kernel.

CVSS severity5.5
Medium
EPSS probability0.32%
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 nf_tables in Red Hat Enterprise Linux 8 and 9 allows attackers to crash the kernel through a dynset request. nft_dynset_init compares a crafted expression against an indexed set expression without first ensuring the index is below the declared expression count, so an extra expression dereferences a NULL slot. Exploitation requires local access plus CAP_NET_ADMIN; successful triggering interrupts the host by crashing the operating-system kernel.

The record

CVE
CVE-2023-6622
Published
Dec 8, 2023
Updated
Nov 6, 2025
Vendor
Red Hat
Product
Red Hat Enterprise Linux 8
Classifications
CWE-476, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Dec 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 6, 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 privilegesadmin

What is affected?

Red Hat · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.
Red Hat · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.

Published CVSS scores

5.5Red Hat, Inc.CVSS: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)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

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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