CVE-2026-64525

Local denial of service via serialized RCU waits

Published Jul 25, 2026 · Updated Jul 25, 2026

Denial of service in affected Linux Kernel releases allows local users to exhaust memory by rapidly creating network namespaces. The xfrm_policy_fini() exit handler performs a blocking synchronize_rcu() once per namespace, serializing full RCU grace periods during batched cleanup. Sustained unshare(CLONE_NEWNET) activity is required; cleanup_net() can stall, kernel objects and per-CPU memory accumulate, and memory-control-group OOMs follow.

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

What happened

Denial of service in affected Linux Kernel releases allows local users to exhaust memory by rapidly creating network namespaces. The xfrm_policy_fini() exit handler performs a blocking synchronize_rcu() once per namespace, serializing full RCU grace periods during batched cleanup. Sustained unshare(CLONE_NEWNET) activity is required; cleanup_net() can stall, kernel objects and per-CPU memory accumulate, and memory-control-group OOMs follow.

The record

CVE
CVE-2026-64525
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.001
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=069daad4f2ae9c5c108131995529d5f02392c446 <3e52417318473782012b236d0325bf7d2266a597
  2. Affected versionversion=069daad4f2ae9c5c108131995529d5f02392c446 <d14ae8ef88c2c6590e107db61b6adce148cec7b3
  3. Affected versionversion=33a3149dd81a1e2f52b80ee1e0fc380b39f3d028
  4. Affected versionversion=3733fce2871c9bca9dd18a1a23b1432ea215a094 <91cc13978ab0bc6f669139f53e7e613a860d10e0
  5. Affected versionversion=438b1f668ad58f46ce699bb48e4698a7839e3f9e <bca6386dc08750fc7cdcbc7683473748ba3114b9
  6. Affected versionversion=6.12.83 <6.12.93
  7. Affected versionversion=6.18.24 <6.18.35
  8. Affected versionversion=6.19.14 <6.20
  9. Affected versionversion=6.6.136 <6.7
  10. Affected versionversion=7.0
  11. Affected versionversion=b66920a3348c0f63ba18365248fa21fbf0b3a937

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=069daad4f2ae9c5c108131995529d5f02392c446 <3e52417318473782012b236d0325bf7d2266a597; version=069daad4f2ae9c5c108131995529d5f02392c446 <d14ae8ef88c2c6590e107db61b6adce148cec7b3; version=33a3149dd81a1e2f52b80ee1e0fc380b39f3d028; version=3733fce2871c9bca9dd18a1a23b1432ea215a094 <91cc13978ab0bc6f669139f53e7e613a860d10e0; version=438b1f668ad58f46ce699bb48e4698a7839e3f9e <bca6386dc08750fc7cdcbc7683473748ba3114b9; version=6.12.83 <6.12.93; version=6.18.24 <6.18.35; version=6.19.14 <6.20; version=6.6.136 <6.7; version=7.0; version=b66920a3348c0f63ba18365248fa21fbf0b3a937

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.

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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

T1499.001OS Exhaustion Flood

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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