CVE-2026-43327

Local system crash via dummy-hcd reset race

Published May 8, 2026 · Updated May 8, 2026

Improper locking in the Linux Kernel dummy-hcd driver allows local users to crash the system during concurrent USB reset and driver unbind. set_link_state() calls stop_activity(), which can release dum->lock before dum->callback_usage is incremented, allowing unbind to clear dum->driver. A local low-privileged user must win this race; usb_gadget_udc_reset() then receives a NULL driver pointer and triggers an addressing exception.

CVSS severity5.5
Medium
EPSS probability0.10%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper locking in the Linux Kernel dummy-hcd driver allows local users to crash the system during concurrent USB reset and driver unbind. set_link_state() calls stop_activity(), which can release dum->lock before dum->callback_usage is incremented, allowing unbind to clear dum->driver. A local low-privileged user must win this race; usb_gadget_udc_reset() then receives a NULL driver pointer and triggers an addressing exception.

The record

CVE
CVE-2026-43327
Published
May 8, 2026
Updated
May 8, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 8, 2026CVE publishedPublication date reported by the CVE source.
  2. May 8, 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=4.14
  2. Affected versionversion=4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715
  3. Affected versionversion=7b416b9dac6ede26d4ca0c1a88b448b543623ff3
  4. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <218886b2ef2dea7627d3700ab0abaf4bf9d1161f
  5. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <616a63ff495df12863692ab3f9f7b84e3fa7a66d
  6. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <6350c7dd33ab481ef41c931a238361490c32d15c
  7. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <69ab97a693251d6a6093e630060a3c744fd58524
  8. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <791966f85b439b261bf19865cf1c07c065ffb4b4
  9. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <805b1833d6ed6da5086e610578a28e71bb54fbbb
  10. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <cc97fb5969177cccce2e23b31298df220fc7570d
  11. Affected versionversion=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <efbd9441f1e769a7aae1813d497cec09cbdff031
  12. Affected versionversion=8590bc1da625dd4a589eac0fc3aa3cf4f400424d
  13. Affected versionversion=a867d5b932ac4911d3f8a1e63505061b0c81f889
  14. Affected versionversion=e39b17143a5b5aac81f066d455e5d3a9877eb3ae
  15. Affected versionversion=e84b4a008365b7edbd842a063ae28d040a98db25

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.14; version=4f8ae1fcb0dfbb72a7678f81bf01fb7fc85c6715; version=7b416b9dac6ede26d4ca0c1a88b448b543623ff3; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <218886b2ef2dea7627d3700ab0abaf4bf9d1161f; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <616a63ff495df12863692ab3f9f7b84e3fa7a66d; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <6350c7dd33ab481ef41c931a238361490c32d15c; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <69ab97a693251d6a6093e630060a3c744fd58524; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <791966f85b439b261bf19865cf1c07c065ffb4b4; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <805b1833d6ed6da5086e610578a28e71bb54fbbb; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <cc97fb5969177cccce2e23b31298df220fc7570d; version=7dbd8f4cabd96db5a50513de9d83a8105a5ffc81 <efbd9441f1e769a7aae1813d497cec09cbdff031; version=8590bc1da625dd4a589eac0fc3aa3cf4f400424d; version=a867d5b932ac4911d3f8a1e63505061b0c81f889; version=e39b17143a5b5aac81f066d455e5d3a9877eb3ae; version=e84b4a008365b7edbd842a063ae28d040a98db25

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-667Improper Locking
T1499.004Application or System Exploitation

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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