CVE-2026-64423

Local kernel compromise via stale multicast hash

Published Jul 25, 2026 · Updated Jul 25, 2026

Use-after-free in the Linux Kernel IPv4 IGMP subsystem allows local users to compromise the kernel during network-device teardown. ip_mc_destroy_dev() drops multicast-membership references without first unlinking them from mc_hash, so concurrent RCU readers can access reclaimed objects. Reachability requires local execution and user and network namespaces; controlled heap reuse supports disclosure, corruption, privilege escalation, or 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 the Linux Kernel IPv4 IGMP subsystem allows local users to compromise the kernel during network-device teardown. ip_mc_destroy_dev() drops multicast-membership references without first unlinking them from mc_hash, so concurrent RCU readers can access reclaimed objects. Reachability requires local execution and user and network namespaces; controlled heap reuse supports disclosure, corruption, privilege escalation, or a kernel crash.

The record

CVE
CVE-2026-64423
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 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=3.11
  2. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <2ca18df1c2611f70eb3eb487e02ae85eb703b284
  3. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <412ba7def06ffe974ba9a1d862b022362c54ffa5
  4. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <5f42729d74bd6c61306d864423290d92962de4e1
  5. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <76d030ac95e17f91d69a595f17ebc5979700cf9a
  6. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <7993211bde166471dffac074dc965489f86531f8
  7. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <8820b530cb2388503d7418228d03ba074bf7a03e
  8. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9
  9. Affected versionversion=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <f91883031e5a62877a29ce139442973cbea769f1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=3.11; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <2ca18df1c2611f70eb3eb487e02ae85eb703b284; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <412ba7def06ffe974ba9a1d862b022362c54ffa5; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <5f42729d74bd6c61306d864423290d92962de4e1; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <76d030ac95e17f91d69a595f17ebc5979700cf9a; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <7993211bde166471dffac074dc965489f86531f8; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <8820b530cb2388503d7418228d03ba074bf7a03e; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <c6cb5f8ebe1c1a78710c19f102db9fe48b9e6ba9; version=e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 <f91883031e5a62877a29ce139442973cbea769f1

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.

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

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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