CVE-2026-64542

Kernel crash via raced IPv6 device refetch

Published Jul 27, 2026 · Updated Jul 27, 2026

NULL pointer dereference in the Linux Kernel allows local users to crash the kernel through an unprivileged network namespace. accept_untracked_na() re-fetches inet6_dev after its caller validated it, then dereferences idev->cnf.accept_untracked_na without checking whether concurrent addrconf_ifdown() cleared dev->ip6_ptr. Exploitation requires an unprivileged local user with access to a network namespace and a raced IPv6 MTU reduction; the bounded consequence is a kernel oops or panic that interrupts the host.

CVSS severityUnavailable
Unscored
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux Kernel allows local users to crash the kernel through an unprivileged network namespace. accept_untracked_na() re-fetches inet6_dev after its caller validated it, then dereferences idev->cnf.accept_untracked_na without checking whether concurrent addrconf_ifdown() cleared dev->ip6_ptr. Exploitation requires an unprivileged local user with access to a network namespace and a raced IPv6 MTU reduction; the bounded consequence is a kernel oops or panic that interrupts the host.

The record

CVE
CVE-2026-64542
Published
Jul 27, 2026
Updated
Jul 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 27, 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=6.0
  2. Affected versionversion=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <62c719203cb521b64fab74da94a81bdde5c18808
  3. Affected versionversion=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <63d1c23764de2309cedbb779c75188d257a09d9b
  4. Affected versionversion=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <a6450f7cfae57b382cbaf66a577765c9a88b3c58
  5. Affected versionversion=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <d186e942365acece7c56d39da05dd63bf95b280a

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.0; version=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <62c719203cb521b64fab74da94a81bdde5c18808; version=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <63d1c23764de2309cedbb779c75188d257a09d9b; version=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <a6450f7cfae57b382cbaf66a577765c9a88b3c58; version=aaa5f515b16b6b3e137779ffb4c9558bb58c1e75 <d186e942365acece7c56d39da05dd63bf95b280a

Published CVSS scores

No CVSS assessment is available in this record.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

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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