CVE-2026-43167Public exploit

Local denial of service via XFRM reference leak

Published May 6, 2026 · Updated May 6, 2026

Reference-count leakage in the Linux Kernel XFRM subsystem allows local users to exhaust resources by unregistering network devices. xfrm_dev_state_add acquires a net_device reference, but xfrm_dev_unregister does not flush the associated state and policy when NETDEV_UNREGISTER fires. Exploitation requires privileges to configure network devices and IPsec offload state; repeated triggering can deny service through unreleased kernel resources.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reference-count leakage in the Linux Kernel XFRM subsystem allows local users to exhaust resources by unregistering network devices. xfrm_dev_state_add acquires a net_device reference, but xfrm_dev_unregister does not flush the associated state and policy when NETDEV_UNREGISTER fires. Exploitation requires privileges to configure network devices and IPsec offload state; repeated triggering can deny service through unreleased kernel resources.

The record

CVE
CVE-2026-43167
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-911, T1499.004
Attack vector
local
Privileges
admin

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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.12
  2. Affected versionversion=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <166801e49a5b5fc127b8c9e2f110f303cfddfbc3
  3. Affected versionversion=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <4efa91a28576054aae0e6dad9cba8fed8293aef8
  4. Affected versionversion=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <59581778792cbaf8ad788f4a21dc663ce986050e
  5. Affected versionversion=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <8c75c455ecd3bfd2f36abf66edb7021c4fa19ec4
  6. Affected versionversion=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <a3c8fede034fa27892f87c863cbd5493167d17ed

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.12; version=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <166801e49a5b5fc127b8c9e2f110f303cfddfbc3; version=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <4efa91a28576054aae0e6dad9cba8fed8293aef8; version=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <59581778792cbaf8ad788f4a21dc663ce986050e; version=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <8c75c455ecd3bfd2f36abf66edb7021c4fa19ec4; version=d77e38e612a017480157fe6d2c1422f42cb5b7e3 <a3c8fede034fa27892f87c863cbd5493167d17ed

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
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

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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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-911Improper Update of Reference Count
T1499.004Application or System Exploitation

Public exploit references

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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