CVE-2026-23298

System hang via zero-length ucan messages

Published Mar 25, 2026 · Updated Mar 25, 2026

Denial of service in affected Linux kernel branches starting at 4.19 allows attackers to hang the system through the ucan USB-CAN driver. ucan_read_bulk_callback() fails to advance past a device message whose length field is zero, causing an infinite parsing loop. A ucan-compatible USB-CAN device must deliver the malformed message; the reported consequence is a system hang rather than data access or modification.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in affected Linux kernel branches starting at 4.19 allows attackers to hang the system through the ucan USB-CAN driver. ucan_read_bulk_callback() fails to advance past a device message whose length field is zero, causing an infinite parsing loop. A ucan-compatible USB-CAN device must deliver the malformed message; the reported consequence is a system hang rather than data access or modification.

The record

CVE
CVE-2026-23298
Published
Mar 25, 2026
Updated
Mar 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-835, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.19
  2. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <13b646eec3ba1131180803f5aaf1fee23540ad8f
  3. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <1e446fd0582ad8be9f6dafb115fc2e7245f9bea7
  4. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588
  5. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <ab6f075492d37368b4c7b0df7f7fdc2b666887fc
  6. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <bd85f21a6219aeae4389d700c54f1799f4b814e0
  7. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <c7bc62be6c1a60bb21301692009590b1ffda91d9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.19; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <13b646eec3ba1131180803f5aaf1fee23540ad8f; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <1e446fd0582ad8be9f6dafb115fc2e7245f9bea7; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <aa9e0a7fe5efc2f74327fd37d828e9a51d9ff588; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <ab6f075492d37368b4c7b0df7f7fdc2b666887fc; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <bd85f21a6219aeae4389d700c54f1799f4b814e0; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <c7bc62be6c1a60bb21301692009590b1ffda91d9

Published CVSS scores

5.5NIST National Vulnerability DatabaseCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.0Amazon Linux Security CenterCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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