CVE-2026-46103

Local denial of service via ucan memory leak

Published May 27, 2026 · Updated May 27, 2026

Memory leak in the Linux Kernel ucan USB-CAN driver allows local users to exhaust kernel memory through repeated driver unbinds. In ucan_probe(), devm_kzalloc() attaches the control-transfer buffer to the parent USB device, so interface unbind does not release it. Access sufficient to trigger ucan interface unbinds, including probe deferral or configuration changes, is required; repeated cycles consume kernel memory and can interrupt service.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in the Linux Kernel ucan USB-CAN driver allows local users to exhaust kernel memory through repeated driver unbinds. In ucan_probe(), devm_kzalloc() attaches the control-transfer buffer to the parent USB device, so interface unbind does not release it. Access sufficient to trigger ucan interface unbinds, including probe deferral or configuration changes, is required; repeated cycles consume kernel memory and can interrupt service.

The record

CVE
CVE-2026-46103
Published
May 27, 2026
Updated
May 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499.001
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 27, 2026CVE publishedPublication date reported by the CVE source.
  2. May 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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 <10b7b676b78a7bd888d19729b459aad7fc1f428b
  3. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <4b7d07747400cfd7eff1ba7b8b5a7c8d5a58f705
  4. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <c0d3ccc6929e4509076df8f30a4fb1dc5018b0ae
  5. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <c524c124e3094d2de12235a513854c03d06a2b58
  6. Affected versionversion=9f2d3eae88d26c29d96e42983b755940d9169cd9 <fed4626501c871890da287bec62a96e52da1af89

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.19; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <10b7b676b78a7bd888d19729b459aad7fc1f428b; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <4b7d07747400cfd7eff1ba7b8b5a7c8d5a58f705; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <c0d3ccc6929e4509076df8f30a4fb1dc5018b0ae; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <c524c124e3094d2de12235a513854c03d06a2b58; version=9f2d3eae88d26c29d96e42983b755940d9169cd9 <fed4626501c871890da287bec62a96e52da1af89

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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-401Missing Release of Memory after Effective Lifetime
T1499.001OS Exhaustion Flood

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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