---
id: CVE-2026-23298
title: 'can: ucan: Fix infinite loop from zero-length messages'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  can: ucan: Fix infinite loop from zero-length messages

  If a broken ucan device gets a message with the message length field set
  to 0, then the driver will loop for for…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    ca07d3c6eef14d34e6fdeefe55058db045be29dc
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    e7bb6e0606b5f233531aaaad9542d69fbb792115
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    ab6f075492d37368b4c7b0df7f7fdc2b666887fc
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    13b646eec3ba1131180803f5aaf1fee23540ad8f
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    bd85f21a6219aeae4389d700c54f1799f4b814e0
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    c7bc62be6c1a60bb21301692009590b1ffda91d9
  - >-
    Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 <
    1e446fd0582ad8be9f6dafb115fc2e7245f9bea7
  - Linux 4.19
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T21:25:54.286760Z'
published: '2026-03-25'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T21:33:36.600Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-23298'
references:
  - url: 'https://git.kernel.org/stable/c/ca07d3c6eef14d34e6fdeefe55058db045be29dc'
  - url: 'https://git.kernel.org/stable/c/e7bb6e0606b5f233531aaaad9542d69fbb792115'
  - url: 'https://git.kernel.org/stable/c/ab6f075492d37368b4c7b0df7f7fdc2b666887fc'
  - url: 'https://git.kernel.org/stable/c/13b646eec3ba1131180803f5aaf1fee23540ad8f'
  - url: 'https://git.kernel.org/stable/c/bd85f21a6219aeae4389d700c54f1799f4b814e0'
  - url: 'https://git.kernel.org/stable/c/aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588'
  - url: 'https://git.kernel.org/stable/c/c7bc62be6c1a60bb21301692009590b1ffda91d9'
  - url: 'https://git.kernel.org/stable/c/1e446fd0582ad8be9f6dafb115fc2e7245f9bea7'
tags:
  - cve.org
epss: 0.00127
epssPercentile: 0.02419
ingestedAt: '2026-11-05T22:38:32.111Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

can: ucan: Fix infinite loop from zero-length messages

If a broken ucan device gets a message with the message length field set
to 0, then the driver will loop for forever in
ucan_read_bulk_callback(), hanging the system.  If the length is 0, just
skip the message and go on to the next one.

This has been fixed in the kvaser_usb driver in the past in commit
0c73772cd2b8 ("can: kvaser_usb: leaf: Fix potential infinite loop in
command parsers"), so there must be some broken devices out there like
this somewhere.

## Affected

- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < ca07d3c6eef14d34e6fdeefe55058db045be29dc`
- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < e7bb6e0606b5f233531aaaad9542d69fbb792115`
- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < ab6f075492d37368b4c7b0df7f7fdc2b666887fc`
- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < 13b646eec3ba1131180803f5aaf1fee23540ad8f`
- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < bd85f21a6219aeae4389d700c54f1799f4b814e0`
- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588`
- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < c7bc62be6c1a60bb21301692009590b1ffda91d9`
- `Linux >= 9f2d3eae88d26c29d96e42983b755940d9169cd9 < 1e446fd0582ad8be9f6dafb115fc2e7245f9bea7`
- `Linux 4.19`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.