Linux Kernel up to 6.12.95/6.18.38/7.1.3/7.2-rc1 resctrl cpu_to_node out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k2.40

Summaryinfo

A vulnerability classified as very critical was found in Linux Kernel up to 6.12.95/6.18.38/7.1.3/7.2-rc1. Impacted is the function cpu_to_node of the component resctrl. Executing a manipulation can lead to out-of-bounds. This vulnerability appears as CVE-2026-64477. The attack requires local access. There is no available exploit.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.12.95/6.18.38/7.1.3/7.2-rc1 and classified as very critical. This vulnerability affects the function cpu_to_node of the component resctrl. The manipulation with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: x86,fs/resctrl: Prevent out-of-bounds access while offlining CPU when SNC enabled The architecture updates the cpu_mask in a domain's header to track which online CPUs are associated with the domain. When this mask becomes empty the architecture initiates offline of the domain that includes calling on resctrl fs to offline the domain. If it is a monitoring domain in which LLC occupancy is tracked resctrl fs forces the limbo handler to clear all busy RMID state associated with the domain. The limbo handler always reads the current event value associated with a busy RMID irrespective of it being checked as part of regular "is it still busy" check or whether it will be forced released anyway. When reading an RMID on a system with SNC enabled the "logical RMID" is converted to the "physical RMID" and this conversion requires the NUMA node ID of the resctrl monitoring domain that is in turn determined by querying the NUMA node ID of any CPU belonging to the monitoring domain. When the monitoring domain is going offline its cpu_mask is empty causing the NUMA node ID query via cpu_to_node() to be done with "nr_cpu_ids" as argument resulting in an out-of-bounds access. Refactor the limbo handler to skip reading the RMID when the RMID will just be forced to no longer be dirty in the domain anyway. Add a safety check to the architecture's RMID reader to protect against this scenario.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-64477 since 07/19/2026. The exploitation appears to be easy. Local access is required to approach this attack. Additional levels of successful authentication are necessary for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/25/2026).

Upgrading to version 6.12.96, 6.18.39, 7.1.4 or 7.2-rc2 eliminates this vulnerability. Applying the patch ebc300b7ee0c669fa76a7a8858298ff32e296103/be1567992417dc92133e74126de7a6066c825ac9/58c5ec23b1a238eb75cb0aba6f69d8f9e68ef0b2/fc16126cc11d9f507130bf84ab137ee0938c900e is able to eliminate this problem.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.96/6.18.39/7.1.4/7.2-rc2
Patch: ebc300b7ee0c669fa76a7a8858298ff32e296103/be1567992417dc92133e74126de7a6066c825ac9/58c5ec23b1a238eb75cb0aba6f69d8f9e68ef0b2/fc16126cc11d9f507130bf84ab137ee0938c900e

Timelineinfo

07/19/2026 CVE reserved
07/25/2026 +6 days Advisory disclosed
07/25/2026 +0 days VulDB entry created
07/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-64477 (🔒)
GCVE (CVE): GCVE-0-2026-64477
GCVE (VulDB): GCVE-100-383278

Entryinfo

Created: 07/25/2026 19:09
Changes: 07/25/2026 19:09 (59)
Complete: 🔍
Cache ID: 216::103

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