CVE-2026-43084

Kernel crash via cross-queue use-after-free

Published May 6, 2026 · Updated May 6, 2026

Use-after-free in Linux Kernel 6.12.75 through 6.12.82, 6.18.14 through 6.18.23, and 6.19.4 through 6.19.13 allows local users to crash the kernel. nfqnl_recv_verdict walks a global hash table after another CPU frees an nf_queue_entry with kfree, causing the parallel traversal to dereference stale memory. Reachability requires local low-privilege access and concurrent NFQUEUE verdict processing across queues; the grounded consequence is a kernel crash.

CVSS severity7.8
High
EPSS probability0.13%
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 Linux Kernel 6.12.75 through 6.12.82, 6.18.14 through 6.18.23, and 6.19.4 through 6.19.13 allows local users to crash the kernel. nfqnl_recv_verdict walks a global hash table after another CPU frees an nf_queue_entry with kfree, causing the parallel traversal to dereference stale memory. Reachability requires local low-privilege access and concurrent NFQUEUE verdict processing across queues; the grounded consequence is a kernel crash.

The record

CVE
CVE-2026-43084
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 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=371de2bef6582a3f58049b3d18e190924af9c9a0 <22730cb96093b5be0609063bbb1923dbecd61252
  2. Affected versionversion=6.12.75 <6.12.83
  3. Affected versionversion=6.18.14 <6.18.24
  4. Affected versionversion=6.19.4 <6.19.14
  5. Affected versionversion=70e2e3ce4f6841e12ec1c104fc76c0e707398ec4 <9e5ebef91120d2764aefe557c3a484b6288f341f
  6. Affected versionversion=870e3e63da8e88daffe9d692a025c711658018a8 <41e3652a178cb0eecd48e0e6e27fbb73a004046a
  7. Affected versionversion=e19079adcd26a25d7d3e586b1837493361fdf8b6 <936206e3f6ff411581e615e930263d6f8b78df9d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=371de2bef6582a3f58049b3d18e190924af9c9a0 <22730cb96093b5be0609063bbb1923dbecd61252; version=6.12.75 <6.12.83; version=6.18.14 <6.18.24; version=6.19.4 <6.19.14; version=70e2e3ce4f6841e12ec1c104fc76c0e707398ec4 <9e5ebef91120d2764aefe557c3a484b6288f341f; version=870e3e63da8e88daffe9d692a025c711658018a8 <41e3652a178cb0eecd48e0e6e27fbb73a004046a; version=e19079adcd26a25d7d3e586b1837493361fdf8b6 <936206e3f6ff411581e615e930263d6f8b78df9d

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.3UbuntuCVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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
T1499Endpoint Denial of Service

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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