CVE-2023-6536 | Kernel: null pointer dereference in __nvmet_req_complete

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.

Published: 2024-02-07 Last update: 2025-11-04 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-6536 is rated Low Risk (27.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-6536

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.17% 0.02% -0.14%
2 2025-11-18 0.02% 0.17% +0.14%
3 2025-04-15 — 0.02% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-6536

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-6536

OS Trackers for CVE-2023-6536

vendor priority summary link
debian not yet assigned CVE-2023-6536 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-6536
redhat medium — https://access.redhat.com/security/cve/CVE-2023-6536
suse medium — https://www.suse.com/security/cve/CVE-2023-6536/
ubuntu medium CVE-2023-6536 medium priority: Ubuntu including 167 source packages (linux, linux-allwinner, …), 1873 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1428, released 181, ignored 152, not-affected 110, needs-triage 2. https://ubuntu.com/security/CVE-2023-6536

Affected software / configurations for CVE-2023-6536

Vendor Product Version Raw CPE
linux linux_kernel >= 5.0, < 5.4.268 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.5, < 5.10.209 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.11, < 5.15.148 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 5.16, < 6.1.75 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.2, < 6.6.14 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
linux linux_kernel >= 6.7, < 6.7.2 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus 8.6 cpe:2.3:a:redhat:codeready_linux_builder_eus:8.6:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus 9.2 cpe:2.3:a:redhat:codeready_linux_builder_eus:9.2:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus_for_power_little_endian_eus 8.6_ppc64le cpe:2.3:a:redhat:codeready_linux_builder_eus_for_power_little_endian_eus:8.6_ppc64le:*:*:*:*:*:*:*
redhat codeready_linux_builder_eus_for_power_little_endian_eus 9.2_ppc64le cpe:2.3:a:redhat:codeready_linux_builder_eus_for_power_little_endian_eus:9.2_ppc64le:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_arm64_eus 8.6_aarch64 cpe:2.3:a:redhat:codeready_linux_builder_for_arm64_eus:8.6_aarch64:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_arm64_eus 9.2_aarch64 cpe:2.3:a:redhat:codeready_linux_builder_for_arm64_eus:9.2_aarch64:*:*:*:*:*:*:*
redhat codeready_linux_builder_for_ibm_z_systems_eus 9.2_s390x cpe:2.3:a:redhat:codeready_linux_builder_for_ibm_z_systems_eus:9.2_s390x:*:*:*:*:*:*:*
redhat enterprise_linux 8.0 cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
redhat enterprise_linux 9.0 cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*
redhat enterprise_linux_eus 8.6 cpe:2.3:o:redhat:enterprise_linux_eus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_eus 9.2 cpe:2.3:o:redhat:enterprise_linux_eus:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 8.6_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:8.6_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_arm_64_eus 9.2_aarch64 cpe:2.3:o:redhat:enterprise_linux_for_arm_64_eus:9.2_aarch64:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 8.6_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:8.6_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_ibm_z_systems_eus 9.2_s390x cpe:2.3:o:redhat:enterprise_linux_for_ibm_z_systems_eus:9.2_s390x:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 8.6_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:8.6_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_power_little_endian_eus 9.2_ppc64le cpe:2.3:o:redhat:enterprise_linux_for_power_little_endian_eus:9.2_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_for_real_time 9.2 cpe:2.3:o:redhat:enterprise_linux_for_real_time:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_for_real_time_for_nfv 9.2 cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 8.6 cpe:2.3:o:redhat:enterprise_linux_server_aus:8.6:*:*:*:*:*:*:*
redhat enterprise_linux_server_aus 9.2 cpe:2.3:o:redhat:enterprise_linux_server_aus:9.2:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 8.6_ppc64le cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:8.6_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions 9.2_ppc64le cpe:2.3:o:redhat:enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions:9.2_ppc64le:*:*:*:*:*:*:*
redhat enterprise_linux_server_tus 8.6 cpe:2.3:o:redhat:enterprise_linux_server_tus:8.6:*:*:*:*:*:*:*
redhat virtualization_host 4.0 cpe:2.3:a:redhat:virtualization_host:4.0:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

References for CVE-2023-6536

URL Tags
https://access.redhat.com/errata/RHSA-2024:0723 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:0724 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:0725 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:0881 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:0897 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:1248 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:2094 Third Party Advisory
https://access.redhat.com/errata/RHSA-2024:3810 Third Party Advisory
https://access.redhat.com/security/cve/CVE-2023-6536 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2254052 Issue Tracking
https://lists.debian.org/debian-lts-announce/2024/06/msg00016.html
https://lists.fedoraproject.org/archives/list/[email protected]/message/ZFYW6R64GPLUOXSQBJI3JBUX3HGLAYPP/
https://security.netapp.com/advisory/ntap-20240415-0001/
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