CVE-2026-23449

Kernel crash via unlocked TEQL qdisc reset

Published Apr 3, 2026 · Updated Apr 3, 2026

Double-free in the Linux Kernel TEQL scheduler allows local users to crash the system when a lockless qdisc is configured as root. The TEQL reset path calls qdisc_reset without the required sequence lock, allowing teardown to race with the packet datapath and release the same socket-buffer data twice. Exploitation requires local low-privileged access and the non-default TEQL configuration; the demonstrated 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

Double-free in the Linux Kernel TEQL scheduler allows local users to crash the system when a lockless qdisc is configured as root. The TEQL reset path calls qdisc_reset without the required sequence lock, allowing teardown to race with the packet datapath and release the same socket-buffer data twice. Exploitation requires local low-privileged access and the non-default TEQL configuration; the demonstrated consequence is a kernel crash.

The record

CVE
CVE-2026-23449
Published
Apr 3, 2026
Updated
Apr 3, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-415, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 3, 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=4.18
  2. Affected versionversion=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <21c89a0a8de7eadad8d385645a95b3233f23130e
  3. Affected versionversion=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <4a233447b941db451ea5f5a0942cffd0f7f7eaae
  4. Affected versionversion=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <4e8ebc4c18ea8213d28e6cb867d18fcc67daca21
  5. Affected versionversion=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <66360460cab63c248ca5b1070a01c0c29133b960
  6. Affected versionversion=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <afbc79a7770b230a9f24bd39271209d6b3682c5f
  7. Affected versionversion=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <e9c66d3e7d8557b3308e55c613aa07254fe97611

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.18; version=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <21c89a0a8de7eadad8d385645a95b3233f23130e; version=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <4a233447b941db451ea5f5a0942cffd0f7f7eaae; version=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <4e8ebc4c18ea8213d28e6cb867d18fcc67daca21; version=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <66360460cab63c248ca5b1070a01c0c29133b960; version=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <afbc79a7770b230a9f24bd39271209d6b3682c5f; version=96009c7d500efdd5534e83b2e3eb2c58d4b137ae <e9c66d3e7d8557b3308e55c613aa07254fe97611

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
5.5OracleCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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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-415Double Free
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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