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Fencer Vulns
medium 6.5

CVE-2023-6535 json

Kernel: null pointer dereference in nvmet_tcp_execute_request

published 2024-02-07 2 y ago modified 2026-11-05 3 d ago also EUVD-2023-58766

cvss
6.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.5%
EPSS 1.5% chance of exploitation in 30 days, percentile 75%
public exploits
0
none known

Summary

A flaw was found in the Linux kernel's NVMe driver. This issue may allow an unauthenticated malicious actor to send a set of crafted TCP packages when using NVMe over TCP, leading the NVMe driver to a NULL pointer dereference in the NVMe driver, causing kernel panic and a denial of service.

Patch / fix

  • Red Hat Red Hat Enterprise Linux 8 0:4.18.0-513.18.1.el8_9, 0:4.18.0-513.18.1.rt7.320.el8_9
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support 0:4.18.0-372.91.1.el8_6
  • Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support 0:4.18.0-477.58.1.el8_8
  • Red Hat Red Hat Enterprise Linux 9 0:5.14.0-362.24.1.el9_3
  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support 0:5.14.0-284.52.1.el9_2, 0:5.14.0-284.52.1.rt14.337.el9_2
  • Red Hat Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 0:4.18.0-372.91.1.el8_6
  • Red Hat RHOL-5.8-RHEL-9 v0.1.0-224, v0.1.0-525, v0.4.0-247, v0.28.1-56, v1.0.0-479, v1.1.0-227, v2.9.6-14, v5.8.1-470, v5.8.6-2, v5.8.6-5, v5.8.6-7, v5.8.6-10, v5.8.6-11, v5.8.6-19, v5.8.6-22, v5.8.6-24, v6.8.1-407
  • linux Debian 12 6.1.76-1
  • linux Debian 14, Debian 13 6.6.15-1

debian advisories DEBIAN-CVE-2023-6535

  • linux Ubuntu 20.04 LTS 5.4.0-176.196
  • linux Ubuntu 22.04 LTS 5.15.0-102.112
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1122.132
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1057.63
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1126.135
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1055.63
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1054.59
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1069.74

ubuntu advisories UBUNTU-CVE-2023-6535

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

  • perf rhev hypervisor 4.4, RHEL 8.6 EUS 4.18.0-372.91.1.el8_6
  • kernel RHEL 9 5.14.0-362.24.1.el9_3
  • rv RHEL 9 5.14.0-362.24.1.el9_3
  • perf RHEL 9 5.14.0-362.24.1.el9_3
  • rtla RHEL 9 5.14.0-362.24.1.el9_3
  • bpftool RHEL 9 7.2.0-362.24.1.el9_3
  • libperf RHEL 9 5.14.0-362.24.1.el9_3
  • kernel-rt RHEL 9 5.14.0-362.24.1.el9_3

red hat advisories RHSA-2024:0724RHSA-2024:0723RHSA-2024:0725RHSA-2024:1248RHSA-2024:3810RHSA-2024:0881

  • kernel-syms SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-122.216.1
  • kernel-source SLES for SAP 12 SP5, SLES 12 SP5 4.12.14-122.216.1
  • kernel-default SLES for SAP 12 SP5, SLES 12 SP5, SLE Workstation Extension 12 SP5 +2 more 4.12.14-122.216.1
  • kernel-obs-build SLE Software Development Kit 12 SP5 4.12.14-122.216.1
  • kernel-rt SLE Real Time 12 SP5 4.12.14-10.182.1
  • kernel-syms-rt SLE Real Time 12 SP5 4.12.14-10.182.1
  • kernel-rt_debug SLE Real Time 12 SP5 4.12.14-10.182.1
  • kernel-source-rt SLE Real Time 12 SP5 4.12.14-10.182.1

suse advisories SUSE-SU-2024:1870-1SUSE-SU-2024:1646-1SUSE-SU-2024:1643-1SUSE-SU-2024:1490-1SUSE-SU-2024:1489-1SUSE-SU-2024:1480-1

  • kernel-source-longterm openSUSE Tumbleweed 6.12.11-1.1
  • kernel-source openSUSE Tumbleweed 6.7.4-1.1

opensuse advisories openSUSE-SU-2025:14705-1openSUSE-SU-2024:13660-1

  • kernel AlmaLinux 8 4.18.0-513.18.1.el8_9
  • perf AlmaLinux 8 4.18.0-513.18.1.el8_9
  • bpftool AlmaLinux 8 4.18.0-513.18.1.el8_9
  • kernel-core AlmaLinux 8 4.18.0-513.18.1.el8_9
  • kernel-tools AlmaLinux 8 4.18.0-513.18.1.el8_9
  • python3-perf AlmaLinux 8 4.18.0-513.18.1.el8_9
  • kernel-modules AlmaLinux 8 4.18.0-513.18.1.el8_9
  • kernel-zfcpdump AlmaLinux 8 4.18.0-513.18.1.el8_9

almalinux advisories ALSA-2024:0897

  • kernel Rocky Linux 9 5.14.0-362.24.1.el9_3.cloud.0.6

rocky linux advisories RXSA-2024:1248

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-2023-6535 updated cvss 6.5

kernel: NULL pointer dereference in nvmet_tcp_execute_request

  • Red Hat Enterprise Linux 9 kernel-rt, kernel-rt-kvm, kernel-rt-core, kernel-rt-modules, kernel-rt-debug-kvm, kernel-rt-debug-core, +12 more
    affected: workaround, no fix available “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.”
  • Red Hat CodeReady Linux Builder (v. 8) kernel-debuginfo-common-x86_64 4.18.0-513.18.1.el8_9, kernel-debuginfo-common-aarch64 4.18.0-513.18.1.el8_9, kernel-debuginfo-common-ppc64le 4.18.0-513.18.1.el8_9
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0897
  • Red Hat CodeReady Linux Builder (v. 9) libperf 5.14.0-362.24.1.el9_3, kernel-debuginfo-common-s390x 5.14.0-362.24.1.el9_3, kernel-debuginfo-common-x86_64 5.14.0-362.24.1.el9_3, kernel-debuginfo-common-aarch64 5.14.0-362.24.1.el9_3, kernel-debuginfo-common-ppc64le 5.14.0-362.24.1.el9_3
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:1248
  • Red Hat CodeReady Linux Builder EUS (v.8.6) kernel-debuginfo-common-x86_64 4.18.0-372.91.1.el8_6, kernel-debuginfo-common-aarch64 4.18.0-372.91.1.el8_6, kernel-debuginfo-common-ppc64le 4.18.0-372.91.1.el8_6
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0724
  • Red Hat CodeReady Linux Builder EUS (v.8.8) kernel-debuginfo-common-x86_64 4.18.0-477.58.1.el8_8, kernel-debuginfo-common-aarch64 4.18.0-477.58.1.el8_8, kernel-debuginfo-common-ppc64le 4.18.0-477.58.1.el8_8
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:3810
  • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-debuginfo-common-s390x 5.14.0-284.52.1.el9_2, kernel-debuginfo-common-x86_64 5.14.0-284.52.1.el9_2, kernel-debuginfo-common-aarch64 5.14.0-284.52.1.el9_2, kernel-debuginfo-common-ppc64le 5.14.0-284.52.1.el9_2
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0723
  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-362.24.1.el9_3, perf 5.14.0-362.24.1.el9_3, rtla 5.14.0-362.24.1.el9_3, kernel-devel-matched 5.14.0-362.24.1.el9_3, kernel-64k-devel-matched 5.14.0-362.24.1.el9_3, kernel-debug-devel-matched 5.14.0-362.24.1.el9_3, +6 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:1248
  • Red Hat Enterprise Linux AppStream EUS (v.9.2) perf 5.14.0-284.52.1.el9_2, rtla 5.14.0-284.52.1.el9_2, kernel-devel-matched 5.14.0-284.52.1.el9_2, kernel-64k-devel-matched 5.14.0-284.52.1.el9_2, kernel-debug-devel-matched 5.14.0-284.52.1.el9_2, kernel-debuginfo-common-s390x 5.14.0-284.52.1.el9_2, +5 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0723
show 14 more
  • Red Hat Enterprise Linux BaseOS (v. 8) perf 4.18.0-513.18.1.el8_9, kernel 4.18.0-513.18.1.el8_9, bpftool 4.18.0-513.18.1.el8_9, kernel-core 4.18.0-513.18.1.el8_9, kernel-tools 4.18.0-513.18.1.el8_9, python3-perf 4.18.0-513.18.1.el8_9, +15 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0897
  • Red Hat Enterprise Linux BaseOS (v. 9) bpftool 7.2.0-362.24.1.el9_3, kernel 5.14.0-362.24.1.el9_3, kernel-64k 5.14.0-362.24.1.el9_3, kernel-core 5.14.0-362.24.1.el9_3, kernel-tools 5.14.0-362.24.1.el9_3, python3-perf 5.14.0-362.24.1.el9_3, +28 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:1248
  • Red Hat Enterprise Linux BaseOS EUS (v.8.6) perf 4.18.0-372.91.1.el8_6, kernel 4.18.0-372.91.1.el8_6, bpftool 4.18.0-372.91.1.el8_6, kernel-core 4.18.0-372.91.1.el8_6, kernel-tools 4.18.0-372.91.1.el8_6, python3-perf 4.18.0-372.91.1.el8_6, +15 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0724
  • Red Hat Enterprise Linux BaseOS EUS (v.8.8) perf 4.18.0-477.58.1.el8_8, kernel 4.18.0-477.58.1.el8_8, bpftool 4.18.0-477.58.1.el8_8, kernel-core 4.18.0-477.58.1.el8_8, kernel-tools 4.18.0-477.58.1.el8_8, python3-perf 4.18.0-477.58.1.el8_8, +15 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:3810
  • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool 7.0.0-284.52.1.el9_2, kernel 5.14.0-284.52.1.el9_2, kernel-64k 5.14.0-284.52.1.el9_2, kernel-core 5.14.0-284.52.1.el9_2, kernel-tools 5.14.0-284.52.1.el9_2, python3-perf 5.14.0-284.52.1.el9_2, +28 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0723
  • Red Hat Enterprise Linux for Real Time (v. 8) kernel-rt 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-core 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-modules 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-debug-core 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-debug-modules 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-modules-extra 4.18.0-513.18.1.rt7.320.el8_9, +2 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0881
  • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-362.24.1.el9_3, kernel-rt-core 5.14.0-362.24.1.el9_3, kernel-rt-modules 5.14.0-362.24.1.el9_3, kernel-rt-debug-core 5.14.0-362.24.1.el9_3, kernel-rt-modules-core 5.14.0-362.24.1.el9_3, kernel-rt-debug-modules 5.14.0-362.24.1.el9_3, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:1248
  • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-core 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-modules 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-debug-core 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-modules-core 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-debug-modules 5.14.0-284.52.1.rt14.337.el9_2, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0725
  • Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-kvm 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-core 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-modules 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-debug-kvm 4.18.0-513.18.1.rt7.320.el8_9, kernel-rt-debug-core 4.18.0-513.18.1.rt7.320.el8_9, +4 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0881
  • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-362.24.1.el9_3, kernel-rt-kvm 5.14.0-362.24.1.el9_3, kernel-rt-core 5.14.0-362.24.1.el9_3, kernel-rt-modules 5.14.0-362.24.1.el9_3, kernel-rt-debug-kvm 5.14.0-362.24.1.el9_3, kernel-rt-debug-core 5.14.0-362.24.1.el9_3, +6 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:1248
  • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-kvm 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-core 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-modules 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-debug-kvm 5.14.0-284.52.1.rt14.337.el9_2, kernel-rt-debug-core 5.14.0-284.52.1.rt14.337.el9_2, +6 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0725
  • Red Hat Virtualization 4 Hypervisor for RHEL 8 perf 4.18.0-372.91.1.el8_6, kernel-debuginfo-common-x86_64 4.18.0-372.91.1.el8_6
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:0724
  • Red Hat RHOL 5.8 for RHEL 9 openshift-logging/fluentd-rhel9 v5.8.6-5, openshift-logging/vector-rhel9 v0.28.1-56, openshift-logging/eventrouter-rhel9 v0.4.0-247, openshift-logging/logging-loki-rhel9 v2.9.6-14, openshift-logging/loki-rhel9-operator v5.8.6-10, openshift-logging/loki-operator-bundle v5.8.6-24, +11 more
    fixed: vendor fix “To mitigate this issue, prevent module nvmet-tcp from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.” RHSA-2024:2094
  • 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
    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
2 y ago

Exploit prediction

1.55% chance of exploitation in the next 30 days, higher than 75% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support
  • Red Hat Red Hat Virtualization 4 for Red Hat Enterprise Linux 8
  • Red Hat RHOL-5.8-RHEL-9
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7

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.