CVE-2023-6121 Redhat CVE debrief

Who should care

Linux administrators and platform teams running NVMe-over-Fabrics over TCP, especially on distributions or appliances that ship affected Linux kernel builds. Based on the source corpus, Red Hat Enterprise Linux 6.0, 7.0, 8.0, and 9.0 are listed as vulnerable CPE criteria, and downstream vendors also reference the issue in their advisories.

Technical summary

The vulnerability is an out-of-bounds read in the NVMe-oF/TCP subsystem of the Linux kernel. The supplied description says a remote attacker may send a crafted TCP packet that can trigger a heap-based buffer overflow, causing kmalloc data to be printed and potentially leaked to dmesg. NVD maps the issue to CWE-125 and gives it a network-reachable CVSS vector of AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N, indicating low-privilege access is required and the primary impact is limited confidentiality leakage.

Defensive priority

Medium. The issue is network-triggerable and can expose kernel memory contents, but the supplied CVSS vector indicates limited confidentiality impact and no integrity or availability impact. Prioritize systems that expose NVMe-oF/TCP services or rely on kernel builds identified by vendor advisories.

Recommended defensive actions

• Apply vendor kernel updates or errata referenced for CVE-2023-6121 as soon as practical.
• Prioritize externally reachable NVMe-oF/TCP hosts and storage nodes for patching.
• Review downstream vendor advisories and issue tracking referenced in the source corpus to confirm the exact fixed builds for your distribution.
• If immediate patching is not possible, reduce exposure of NVMe-oF/TCP endpoints to only trusted management or storage networks.
• Validate that logging and monitoring coverage includes unexpected kernel-ring-buffer messages on affected systems.

Evidence notes

All claims are grounded in the supplied NVD-derived source item and its listed references. The source description states the issue is an out-of-bounds read in Linux NVMe-oF/TCP that may leak kmalloc data into dmesg. The metadata lists CWE-125, CVSS vector AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N, and vulnerable CPE criteria for Red Hat Enterprise Linux 6.0, 7.0, 8.0, and 9.0. The reference set also includes Red Hat errata, a Red Hat bug tracker entry, Debian LTS, and Siemens advisories, showing downstream vendor handling in the corpus. Published date used: 2023-11-16; modified date used: 2026-05-12.

Official resources