CVE-2026-23448
Description
A flaw was found in the Linux kernel's cdc_ncm module. An incorrect bounds check in the cdc_ncm_rx_verify_ndp16() function, responsible for validating Network Data Protocol (NDP) entries, allows Datagram Pointer Entries (DPE) to extend beyond the intended buffer. This can lead to an out-of-bounds read when cdc_ncm_rx_fixup() processes these entries, potentially resulting in information disclosure or a denial of service.
Statement
This vulnerability affects systems using USB CDC NCM (Network Control Model) devices such as USB tethering adapters and mobile broadband modems. Exploitation requires either a malicious USB device or crafted network packets to a connected CDC NCM device. The out-of-bounds read could leak kernel memory or cause a crash.
Mitigation
To mitigate this issue, prevent the cdc_ncm module from being loaded. See https://access.redhat.com/solutions/41278 for instructions. Note this will disable USB CDC NCM network devices.
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 | 5.5 | 7.8 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
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