Skip to content
Noroxi
NVD / CVE Program· CNA Linux

CVE-2026-64248: MIPS: smp: report dying CPU to RCU in stop_this_cpu()

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.15% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 6.1.178, 6.12.95, 6.18.38; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 6.1.178, 6.12.95, 6.18.38; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: MIPS: smp: report dying CPU to RCU in stop_this_cpu() smp_send_stop() parks all secondary CPUs in stop_this_cpu(). The function marks the CPU offline for the scheduler via set_cpu_online(false) but never informs RCU, so RCU keeps expecting a quiescent state from CPUs that are now spinning forever with interrupts disabled. As long as nothing waits for an RCU grace period after smp_send_stop() this is harmless, which is why it went unnoticed. Since commit 91840be8f710 ("irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT") however, irq_work_sync() calls synchronize_rcu() on architectures without an irq_work self-IPI, i.e. where arch_irq_work_has_interrupt() returns false. That is the asm-generic default used by MIPS. Any irq_work_sync() issued in the reboot/shutdown path after smp_send_stop() then blocks on a grace period that can never complete, hanging the reboot: WARNING: CPU: 0 PID: 15 at kernel/irq_work.c:144 irq_work_queue_on ... rcu: INFO: rcu_sched detected stalls on CPUs/tasks: rcu: Offline CPU 1 blocking current GP. rcu: Offline CPU 2 blocking current GP. rcu: Offline CPU 3 blocking current GP. This issue was noticed on several Realtek MIPS switch SoCs (MIPS interAptiv) and came up during kernel bump downstream in OpenWrt from 6.18.33 to 6.18.34, after the backport of the patch to the 6.18 stable branch. The patch also has been backported all the way back to 6.1. Call rcutree_report_cpu_dead() once interrupts are disabled, mirroring the generic CPU-hotplug offline path, so RCU stops waiting on the parked CPUs and grace periods can still complete. MIPS shuts down all CPUs here without going through the CPU-hotplug mechanism, so this report is not otherwise issued. Reporting a dying CPU to RCU outside the regular hotplug offline path is not unprecedented: arm64 does the same in cpu_die_early(). There it is an exception for a CPU that was coming online and is aborting bringup, rather than the default shutdown action as on MIPS.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Jul 24, 2026
Updated
Nov 8, 2026
EPSS
0.1% · 4th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-64248

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits every 10 minutes on paid plans, on the hour on the free plan.

Your free account also gets you

  • Stack alerts: add the products and versions you run, get the new CVEs that affect them
  • Uptime monitoring: 1 site, instant email when it goes down
  • Add your domain: subdomains and takeover risk scanned every week (1 domain)
  • 10 scans an hour on the security tools, at most 30 a day (3 a day without an account), an API key and MCP
  • All your scans in one panel: findings, what changed in the last scan, a report per domain or per client (PDF, share link)
All free tools

Sign up with email · Have an account? Sign in

Free account, no card. Unfollow any time.

Don't want an account? Get "Exploited this week" by email every MondayDon't want an account? RSS feed for linux records
Is your version affected? Check it

Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

We use this product, ask for help

Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel6.1.175 and later · before 6.1.178
  • linux linux kernel6.6.142 and later · before 6.6.145
  • linux linux kernel6.12.92 and later · before 6.12.95
  • linux linux kernel6.18.34 and later · before 6.18.38
  • linux linux kernel7.0.11 and later · before 7.1
  • linux linux kernel7.1.1 and later · before 7.1.3
  • linux linux kernel7.1

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 81b582784518196eff1050212a046bc29d3a05dd, 7.1affected
    • 2dc79362302922cb18f35e262712b5e58de65442 and later · before f8a1ef884013dc99f712d3eb75624c7cd3fd94f6affected · git
    • eef4f71b46a9929ac33e968538c9dd5d96a02460 and later · before e1919d026706544cb6e7251ec06e908edd6f34eeaffected · git
    • 684a78183c54c23e70d1cba320f7fc184604210b and later · before 6eda71977ee11c222f8ad4cae4d18d50448e56f4affected · git
    • 18c0456ea2615b1a743a6db739c74411c3b42bc6 and later · before f9b57a0015c241274651f4b36627f56b1b5a8651affected · git
    • 91840be8f710370607f949a627e070896faeddb8 and later · before 9fef09df42df55ab819b285ea892e0fc1b95a9c4affected · git
    • 91840be8f710370607f949a627e070896faeddb8 and later · before 9f3f3bdc6d9dac1a5a8262ee7ad0f2ff1527a7e7affected · git
    • 6.1.175 and later · before 6.1.178affected · semver
    • 6.6.142 and later · before 6.6.145affected · semver
    • 6.12.92 and later · before 6.12.95affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:13linuxbefore 6.12.95-16.12.95-1
Debian:14linuxbefore 7.1.3-17.1.3-1
openSUSE:Tumbleweedkernel-sourcebefore 7.1.7-1.17.1.7-1.1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64246Jul 24, 2026 · power: reset: linkstation-poweroff: fix use-after-free in the linkstation_poweroff_init()
    31Monitor
  • ← EarlierCVE-2026-64247Jul 24, 2026 · KVM: x86: hyper-v: Bound the bank index when querying sparse banks
    33Monitor
  • Later →CVE-2026-64249Jul 24, 2026 · fpga: region: fix use-after-free in child_regions_with_firmware()
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux6.1.178Vendor (CNA)
Linux Linux6.12.95Vendor (CNA)
Linux Linux6.18.38Vendor (CNA)
Linux Linux6.6.145Vendor (CNA)
Linux Linux6eda71977ee11c222f8ad4cae4d18d50448e56f4Vendor (CNA)
Linux Linux7.1Vendor (CNA)
Linux Linux9f3f3bdc6d9dac1a5a8262ee7ad0f2ff1527a7e7Vendor (CNA)
Linux Linux9fef09df42df55ab819b285ea892e0fc1b95a9c4Vendor (CNA)
Linux Linuxe1919d026706544cb6e7251ec06e908edd6f34eeVendor (CNA)
Linux Linuxf8a1ef884013dc99f712d3eb75624c7cd3fd94f6Vendor (CNA)
Linux Linuxf9b57a0015c241274651f4b36627f56b1b5a8651Vendor (CNA)
azl3 kernel 6.6.144.1-1 on Azure Linux 3.06.6.145.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
opensuse:kernel-source7.1.7-1.1 · openSUSE:TumbleweedPackage registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records