CVE-2026-31558

Kernel memory access via negative vCPU index

Published Apr 24, 2026 · Updated Apr 24, 2026

Out-of-bounds read in LoongArch KVM in Linux Kernel 6.10 through 6.19.10 allows local users to read outside the vCPU map. kvm_get_vcpu_by_cpuid() checks only the upper bound before using its signed cpuid argument to index kvm_arch::phyid_map::phys_map[]. Exploitation requires low-privileged local access to a LoongArch host with KVM enabled; public records do not identify the trigger path.

CVSS severity8.8
High
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds read in LoongArch KVM in Linux Kernel 6.10 through 6.19.10 allows local users to read outside the vCPU map. kvm_get_vcpu_by_cpuid() checks only the upper bound before using its signed cpuid argument to index kvm_arch::phyid_map::phys_map[]. Exploitation requires low-privileged local access to a LoongArch host with KVM enabled; public records do not identify the trigger path.

The record

CVE
CVE-2026-31558
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.10
  2. Affected versionversion=73516e9da512adc63ba3859fbd82a21f6257348f <2db06c15d8c7a0ccb6108524e16cd9163753f354
  3. Affected versionversion=73516e9da512adc63ba3859fbd82a21f6257348f <47857b05bd50db01e211a1b6f513d57901cd3e6b
  4. Affected versionversion=73516e9da512adc63ba3859fbd82a21f6257348f <596c3f8069c4792f22fce8c4452f44410032d910
  5. Affected versionversion=73516e9da512adc63ba3859fbd82a21f6257348f <878cf6acb4fd8ab4126cf9d369a5bb0e23123418

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.10; version=73516e9da512adc63ba3859fbd82a21f6257348f <2db06c15d8c7a0ccb6108524e16cd9163753f354; version=73516e9da512adc63ba3859fbd82a21f6257348f <47857b05bd50db01e211a1b6f513d57901cd3e6b; version=73516e9da512adc63ba3859fbd82a21f6257348f <596c3f8069c4792f22fce8c4452f44410032d910; version=73516e9da512adc63ba3859fbd82a21f6257348f <878cf6acb4fd8ab4126cf9d369a5bb0e23123418

Published CVSS scores

8.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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

CWE-125Out-of-bounds Read

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo