CVE-2026-23001

Kernel memory corruption via stale macvlan pointer

Published Jan 25, 2026 · Updated Jan 25, 2026

Use-after-free in the Linux Kernel macvlan driver allows local users to corrupt kernel memory through concurrent source-table changes. macvlan_hash_del_source() leaves an entry->vlan pointer visible until after the RCU grace period, so macvlan_forward_source() can dereference a vlan object already queued for freeing. Triggering the race requires local low-privileged access capable of changing macvlan source entries while traffic is forwarded; successful exploitation can expose kernel data, alter kernel state, or crash the host.

CVSS severity7.8
High
EPSS probability0.19%
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 the Linux Kernel macvlan driver allows local users to corrupt kernel memory through concurrent source-table changes. macvlan_hash_del_source() leaves an entry->vlan pointer visible until after the RCU grace period, so macvlan_forward_source() can dereference a vlan object already queued for freeing. Triggering the race requires local low-privileged access capable of changing macvlan source entries while traffic is forwarded; successful exploitation can expose kernel data, alter kernel state, or crash the host.

The record

CVE
CVE-2026-23001
Published
Jan 25, 2026
Updated
Jan 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 25, 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=3.18
  2. Affected versionversion=79cf79abce71eb7dbc40e2f3121048ca5405cb47 <6dbead9c7677186f22b7981dd085a0feec1f038e
  3. Affected versionversion=79cf79abce71eb7dbc40e2f3121048ca5405cb47 <7470a7a63dc162f07c26dbf960e41ee1e248d80e
  4. Affected versionversion=79cf79abce71eb7dbc40e2f3121048ca5405cb47 <8518712a2ca952d6da2238c6f0a16b4ae5ea3f13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.18; version=79cf79abce71eb7dbc40e2f3121048ca5405cb47 <6dbead9c7677186f22b7981dd085a0feec1f038e; version=79cf79abce71eb7dbc40e2f3121048ca5405cb47 <7470a7a63dc162f07c26dbf960e41ee1e248d80e; version=79cf79abce71eb7dbc40e2f3121048ca5405cb47 <8518712a2ca952d6da2238c6f0a16b4ae5ea3f13

Published CVSS scores

7.8Linux Kernel CNACVSS:3.1/AV:L/AC:L/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

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-416Use After Free
T1068Exploitation for Privilege Escalation

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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