CVE-2025-21838

Local denial of service via post-removal workqueue

Published Mar 7, 2025 · Updated May 11, 2026

Use-after-free in the Linux kernel USB gadget core allows local users to crash the system during gadget device removal. In usb_del_gadget(), flush_work() runs before device_del(), which can schedule gadget->work through DWC3 teardown and leave work pending against the removed gadget. Local low-privileged access and a configured USB gadget using the affected teardown path are required; the published generic score bounds impact to availability.

CVSS severity5.5
Medium
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel USB gadget core allows local users to crash the system during gadget device removal. In usb_del_gadget(), flush_work() runs before device_del(), which can schedule gadget->work through DWC3 teardown and leave work pending against the removed gadget. Local low-privileged access and a configured USB gadget using the affected teardown path are required; the published generic score bounds impact to availability.

The record

CVE
CVE-2025-21838
Published
Mar 7, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 7, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=3.12
  2. Affected versionversion=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <399a45e5237ca14037120b1b895bd38a3b4492ea
  3. Affected versionversion=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <859cb45aefa6de823b2fa7f229fe6d9562c9f3b7
  4. Affected versionversion=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <97695b5a1b5467a4f91194db12160f56da445dfe
  5. Affected versionversion=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <e3bc1a9a67ce33a2e761e6e7b7c2afc6cb9b7266
  6. Affected versionversion=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <f894448f3904d7ad66fecef8f01fe0172629e091

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=3.12; version=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <399a45e5237ca14037120b1b895bd38a3b4492ea; version=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <859cb45aefa6de823b2fa7f229fe6d9562c9f3b7; version=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <97695b5a1b5467a4f91194db12160f56da445dfe; version=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <e3bc1a9a67ce33a2e761e6e7b7c2afc6cb9b7266; version=5702f75375aa9ecf8ad3431aef3fe6ce8c8dbd15 <f894448f3904d7ad66fecef8f01fe0172629e091

Published CVSS scores

5.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
6.0Red HatCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/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-416Use After Free

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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