CVE-2026-31757

Kernel memory exhaustion via unreleased failed-probe URBs

Published May 1, 2026 · Updated May 1, 2026

A memory leak in the Linux Kernel usbio driver allows local users to exhaust kernel memory during failed USB device probing. In usbio_probe(), a failed usb_submit_urb() call returns without freeing the previously allocated URB, so each failed probe permanently consumes kernel memory. Exploitation requires local low-privileged access and repeated USB-device interaction that reaches the affected driver; the bounded impact is host availability through resource exhaustion.

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

A memory leak in the Linux Kernel usbio driver allows local users to exhaust kernel memory during failed USB device probing. In usbio_probe(), a failed usb_submit_urb() call returns without freeing the previously allocated URB, so each failed probe permanently consumes kernel memory. Exploitation requires local low-privileged access and repeated USB-device interaction that reaches the affected driver; the bounded impact is host availability through resource exhaustion.

The record

CVE
CVE-2026-31757
Published
May 1, 2026
Updated
May 1, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-401, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 1, 2026CVE publishedPublication date reported by the CVE source.
  2. May 1, 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=121a0f839dbb397af5fabb701cea3e9983223e50 <1762dc43b983d321180582afba4a0c5185fae04c
  2. Affected versionversion=121a0f839dbb397af5fabb701cea3e9983223e50 <33cfe0709b6bf1a7f1a16d5e8d65d003a71b6a21
  3. Affected versionversion=121a0f839dbb397af5fabb701cea3e9983223e50 <65ff09f48b0e72e4049096a989723406aabcf091
  4. Affected versionversion=6.18

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=121a0f839dbb397af5fabb701cea3e9983223e50 <1762dc43b983d321180582afba4a0c5185fae04c; version=121a0f839dbb397af5fabb701cea3e9983223e50 <33cfe0709b6bf1a7f1a16d5e8d65d003a71b6a21; version=121a0f839dbb397af5fabb701cea3e9983223e50 <65ff09f48b0e72e4049096a989723406aabcf091; version=6.18

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.

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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-401Missing Release of Memory after Effective Lifetime
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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