CVE-2026-23112
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: add bounds checks in nvmet_tcp_build_pdu_iovec nvmet_tcp_build_pdu_iovec() could walk past cmd->req.sg when a PDU length or offset exceeds sg_cnt and then use bogus sg->length/offset values, leading to _copy_to_iter() GPF/KASAN. Guard sg_idx, remaining entries, and sg->length/offset before building the bvec.
Statement
An out of bounds access in the NVMe TCP target can occur in nvmet_tcp_build_pdu_iovec when a crafted PDU length or data offset causes sg_idx to exceed cmd req sg_cnt or causes iteration past the remaining scatterlist entries. This can make the code use bogus sg length and offset values and then crash in _copy_to_iter with a general protection fault or a KASAN report. The issue is network reachable in environments that expose NVMe over TCP to initiators (usually in local networks or by VPN, so for the CVSS keeping AV:A). Impact is a reliable denial of service via kernel crash. In a conservative assessment memory corruption patterns may also be considered for potential confidentiality or integrity impact. The NVME over TCP for the case of being target like this one is (means RHEL system being used by other systems as a storage device) not supported for the Red Hat Enterprise Linux, but could be enabled by administrator anyway.
Mitigation
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.8 | 9.8 | 9.8 |
| Attack Vector | Adjacent Network | Network | Network |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | None | None |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | Low | High | High |
| Integrity Impact | Low | High | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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