CVE-2023-3439Public exploit

Service crash via MCTP device teardown race

Published Jun 28, 2023 · Updated Mar 10, 2025

Use-after-free in Linux kernel 5.15 through 5.18-rc4 allows local users to crash the kernel by racing MCTP device teardown with sends. mctp_unregister() frees mdev->addrs while mctp_sendmsg() can retain a route and read the freed address array in mctp_local_output(). CAP_NET_ADMIN is required to fake device detachment; a successful race causes a kernel use-after-free and service crash.

CVSS severity4.7
Medium
EPSS probability0.35%
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 5.15 through 5.18-rc4 allows local users to crash the kernel by racing MCTP device teardown with sends. mctp_unregister() frees mdev->addrs while mctp_sendmsg() can retain a route and read the freed address array in mctp_local_output(). CAP_NET_ADMIN is required to fake device detachment; a successful race causes a kernel use-after-free and service crash.

The record

CVE
CVE-2023-3439
Published
Jun 28, 2023
Updated
Mar 10, 2025
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1499
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jun 28, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 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=Fixed in kernel 5.18-rc5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=Fixed in kernel 5.18-rc5

Published CVSS scores

4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7CISA-ADPCVSS:3.1/AV:L/AC:H/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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-416Use After Free
T1499Endpoint Denial of Service

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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