CVE-2023-52523

Kernel crash via non-TCP sk_msg redirection

Published Mar 2, 2024 · Updated Aug 5, 2026

NULL pointer dereference in Linux 5.13 through affected 6.x branches allows local users to crash the kernel via BPF sk_msg redirection. The sockmap send path treats a selected non-TCP egress socket as tcp_sock and passes it into TCP-only processing, causing an invalid downcast and kernel NULL pointer dereference. Exploitation requires local BPF socket-map setup with CAP_NET_ADMIN or CAP_BPF; the demonstrated consequence is an oops or panic that interrupts the host.

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

NULL pointer dereference in Linux 5.13 through affected 6.x branches allows local users to crash the kernel via BPF sk_msg redirection. The sockmap send path treats a selected non-TCP egress socket as tcp_sock and passes it into TCP-only processing, causing an invalid downcast and kernel NULL pointer dereference. Exploitation requires local BPF socket-map setup with CAP_NET_ADMIN or CAP_BPF; the demonstrated consequence is an oops or panic that interrupts the host.

The record

CVE
CVE-2023-52523
Published
Mar 2, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 2, 2024CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 2026Record 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=122e6c79efe1c25816118aca9cfabe54e99c2432 <b80e31baa43614e086a9d29dc1151932b1bd7fc5
  2. Affected versionversion=122e6c79efe1c25816118aca9cfabe54e99c2432 <b8f97e47b6fb84fcf2f5a22e725eefb6cf5070c2
  3. Affected versionversion=122e6c79efe1c25816118aca9cfabe54e99c2432 <bc8b89b6963803a123f64aa9494155a037b3d728
  4. Affected versionversion=122e6c79efe1c25816118aca9cfabe54e99c2432 <ded6e448028f0f91b6af35985afca01fa02a9089
  5. Affected versionversion=5.13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=122e6c79efe1c25816118aca9cfabe54e99c2432 <b80e31baa43614e086a9d29dc1151932b1bd7fc5; version=122e6c79efe1c25816118aca9cfabe54e99c2432 <b8f97e47b6fb84fcf2f5a22e725eefb6cf5070c2; version=122e6c79efe1c25816118aca9cfabe54e99c2432 <bc8b89b6963803a123f64aa9494155a037b3d728; version=122e6c79efe1c25816118aca9cfabe54e99c2432 <ded6e448028f0f91b6af35985afca01fa02a9089; version=5.13

Published CVSS scores

5.5Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8Linux kernel CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5UbuntuCVSS: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 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-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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