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Fencer Vulns
medium 4.7

CVE-2023-3439 json

A flaw was found in the MCTP protocol in the Linux kernel.

published 2023-06-28 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-44103

cvss
4.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 27%
public exploits
0
none known

Summary

A flaw was found in the MCTP protocol in the Linux kernel. The function mctp_unregister() reclaims the device's relevant resource when a netcard detaches. However, a running routine may be unaware of this and cause the use-after-free of the mdev->addrs object, potentially leading to a denial of service.

Patch / fix

  • linux Debian 14, Debian 13, Debian 12 5.17.6-1

debian advisories DEBIAN-CVE-2023-3439

  • linux Ubuntu 22.04 LTS 5.15.0-78.85
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1040.45
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1038.46
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1038.43
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1034.37
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1038.43
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1042.49
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1024.29

ubuntu advisories UBUNTU-CVE-2023-3439

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • hyperv-daemons CBL-Mariner 2.0 5.15.126.1-1
  • kernel CBL-Mariner 2.0 5.15.126.1-1

azure linux advisories AZL-27329AZL-27348

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-3439 updated cvss 5.5

kernel: mctp: use-after-free read in mctp_local_output()

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
20 mo ago

Exploit prediction

0.34% chance of exploitation in the next 30 days, higher than 27% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 4.7 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • n/a Linux Kernel (mctp)

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.