CVE-2026-23298

Description

A flaw was found in the Linux kernel's CAN (Controller Area Network) ucan driver. This vulnerability allows a connected ucan device to send a message with a zero-length field. Such a message can trigger an infinite loop within the driver, causing the system to hang. This ultimately leads to a denial of service (DoS), making the system unresponsive.

Statement

This flaw affects systems with ucan USB-CAN adapters. A malicious or broken device can send zero-length messages that cause the driver to enter an infinite loop in ucan_read_bulk_callback(), hanging the system. Physical access to connect the USB device is required. Similar issues have been fixed in other CAN USB drivers (kvaser_usb).

Mitigation

To mitigate this issue, prevent the ucan module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.

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 HatNVDcve.org
Base Score5.55.5N/A
Attack VectorLocalLocalN/A
Attack ComplexityLowLowN/A
Privileges RequiredLowLowN/A
User InteractionNoneNoneN/A
ScopeUnchangedUnchangedN/A
ConfidentialityNoneNoneN/A
Integrity ImpactNoneNoneN/A
Availability ImpactHighHighN/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:N/I:N/A:H

Understanding the Weakness (CWE)

CWE-606

Availability

Technical Impact: DoS: Resource Consumption (CPU)

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