CVE-2026-31553

Guest-to-host memory corruption via scaled descriptor offset

Published Apr 24, 2026 · Updated Apr 24, 2026

Memory corruption in arm64 KVM in Linux Kernel 6.19 through 6.19.10 allows guest OS users to corrupt host-side VM memory. The __kvm_at_swap_desc function casts hva to a u64 pointer before adding an untrusted nonzero byte offset, scaling it by eight and directing a compare-and-swap at the wrong S1 or S2 descriptor address. Reachability requires control of a nested-virtualization-capable guest, hardware Access Flag management, and a trapped arm64 AT instruction; the wrong-address write can corrupt adjacent VM or VMM memory and interrupt execution.

CVSS severity8.8
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in arm64 KVM in Linux Kernel 6.19 through 6.19.10 allows guest OS users to corrupt host-side VM memory. The __kvm_at_swap_desc function casts hva to a u64 pointer before adding an untrusted nonzero byte offset, scaling it by eight and directing a compare-and-swap at the wrong S1 or S2 descriptor address. Reachability requires control of a nested-virtualization-capable guest, hardware Access Flag management, and a trapped arm64 AT instruction; the wrong-address write can corrupt adjacent VM or VMM memory and interrupt execution.

The record

CVE
CVE-2026-31553
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1068
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

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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=6.19
  2. Affected versionversion=f6927b41d57390c597a126063e2e518911976878 <0496acc42fb51eee040b5170cec05cec41385540
  3. Affected versionversion=f6927b41d57390c597a126063e2e518911976878 <4307e05e568782fc92eff651b09ee5dee88a058d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=6.19; version=f6927b41d57390c597a126063e2e518911976878 <0496acc42fb51eee040b5170cec05cec41385540; version=f6927b41d57390c597a126063e2e518911976878 <4307e05e568782fc92eff651b09ee5dee88a058d

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

T1068Exploitation for Privilege Escalation

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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