CVE-2026-31509

System hang via NCI workqueue lock inversion

Published Apr 22, 2026 · Updated Apr 22, 2026

Improper locking in affected Linux kernel NFC NCI builds allows local users to hang the system during NCI device shutdown. nci_close_device flushes the receive and transmit workqueues while holding req_lock, while nci_rx_work can reenter a path that acquires the same lock. The race requires local access to shut down an NCI device while receive work is active, causing a circular wait that blocks system availability.

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 affected Linux kernel NFC NCI builds allows local users to hang the system during NCI device shutdown. nci_close_device flushes the receive and transmit workqueues while holding req_lock, while nci_rx_work can reenter a path that acquires the same lock. The race requires local access to shut down an NCI device while receive work is active, causing a circular wait that blocks system availability.

The record

CVE
CVE-2026-31509
Published
Apr 22, 2026
Updated
Apr 22, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-667, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 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=3.2
  2. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <09143c0e8f3b03517e6233aad42f45c794d8df8e
  3. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <1edc12d2bbcb7a8d0f1088e6fccb9d8c01bb1289
  4. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <4527025d440ce84bf56e75ce1df2e84cb8178616
  5. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <5eef9ebec7f5738f12cadede3545c05b34bf5ac3
  6. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <7ed00a3edc8597fe2333f524401e2889aa1b5edf
  7. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <ca54e904a071aa65ef3ad46ba42d51aaac6b73b4
  8. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <d89b74bf08f067b55c03d7f999ba0a0e73177eb3
  9. Affected versionversion=6a2968aaf50c7a22fced77a5e24aa636281efca8 <eb435d150ca74b4d40f77f1a2266f3636ed64a79

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.2; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <09143c0e8f3b03517e6233aad42f45c794d8df8e; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <1edc12d2bbcb7a8d0f1088e6fccb9d8c01bb1289; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <4527025d440ce84bf56e75ce1df2e84cb8178616; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <5eef9ebec7f5738f12cadede3545c05b34bf5ac3; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <7ed00a3edc8597fe2333f524401e2889aa1b5edf; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <ca54e904a071aa65ef3ad46ba42d51aaac6b73b4; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <d89b74bf08f067b55c03d7f999ba0a0e73177eb3; version=6a2968aaf50c7a22fced77a5e24aa636281efca8 <eb435d150ca74b4d40f77f1a2266f3636ed64a79

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-667Improper Locking
T1499.004Endpoint Denial of Service: Application 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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