CVE-2026-64248

Local reboot hang via unreported stopped CPUs

Published Jul 24, 2026 · Updated Jul 24, 2026

Improper RCU state handling in the Linux kernel allows local users to hang reboot or shutdown on affected MIPS systems. In stop_this_cpu(), smp_send_stop() marks secondary CPUs offline for scheduling but does not report them dead to RCU, leaving grace periods waiting forever. The hang occurs when a later irq_work_sync() calls synchronize_rcu() on MIPS systems without an irq_work self-IPI.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper RCU state handling in the Linux kernel allows local users to hang reboot or shutdown on affected MIPS systems. In stop_this_cpu(), smp_send_stop() marks secondary CPUs offline for scheduling but does not report them dead to RCU, leaving grace periods waiting forever. The hang occurs when a later irq_work_sync() calls synchronize_rcu() on MIPS systems without an irq_work self-IPI.

The record

CVE
CVE-2026-64248
Published
Jul 24, 2026
Updated
Jul 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 24, 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=18c0456ea2615b1a743a6db739c74411c3b42bc6 <f9b57a0015c241274651f4b36627f56b1b5a8651
  2. Affected versionversion=2dc79362302922cb18f35e262712b5e58de65442 <f8a1ef884013dc99f712d3eb75624c7cd3fd94f6
  3. Affected versionversion=6.1.175 <6.1.178
  4. Affected versionversion=6.12.92 <6.12.95
  5. Affected versionversion=6.18.34 <6.18.38
  6. Affected versionversion=6.6.142 <6.6.145
  7. Affected versionversion=684a78183c54c23e70d1cba320f7fc184604210b <6eda71977ee11c222f8ad4cae4d18d50448e56f4
  8. Affected versionversion=7.0.11 <7.1
  9. Affected versionversion=7.1
  10. Affected versionversion=81b582784518196eff1050212a046bc29d3a05dd
  11. Affected versionversion=91840be8f710370607f949a627e070896faeddb8 <9f3f3bdc6d9dac1a5a8262ee7ad0f2ff1527a7e7
  12. Affected versionversion=91840be8f710370607f949a627e070896faeddb8 <9fef09df42df55ab819b285ea892e0fc1b95a9c4
  13. Affected versionversion=eef4f71b46a9929ac33e968538c9dd5d96a02460 <e1919d026706544cb6e7251ec06e908edd6f34ee

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=18c0456ea2615b1a743a6db739c74411c3b42bc6 <f9b57a0015c241274651f4b36627f56b1b5a8651; version=2dc79362302922cb18f35e262712b5e58de65442 <f8a1ef884013dc99f712d3eb75624c7cd3fd94f6; version=6.1.175 <6.1.178; version=6.12.92 <6.12.95; version=6.18.34 <6.18.38; version=6.6.142 <6.6.145; version=684a78183c54c23e70d1cba320f7fc184604210b <6eda71977ee11c222f8ad4cae4d18d50448e56f4; version=7.0.11 <7.1; version=7.1; version=81b582784518196eff1050212a046bc29d3a05dd; version=91840be8f710370607f949a627e070896faeddb8 <9f3f3bdc6d9dac1a5a8262ee7ad0f2ff1527a7e7; version=91840be8f710370607f949a627e070896faeddb8 <9fef09df42df55ab819b285ea892e0fc1b95a9c4; version=eef4f71b46a9929ac33e968538c9dd5d96a02460 <e1919d026706544cb6e7251ec06e908edd6f34ee

Published CVSS scores

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

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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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