CVE-2023-46842

Host crash via uncleared hypercall register halves

Published May 16, 2024 · Updated Nov 4, 2025

Denial of service in the Xen hypervisor allows guest OS users to crash an x86 host through a crafted HVM or PVH hypercall continuation. During continuation handling, 32-bit register translation preserves attacker-controlled high halves, while a later sanity check assumes those halves are clear and triggers a hypervisor consistency failure. Only HVM or PVH guests on x86 systems can reach the flaw; the resulting crash interrupts every guest on the host.

CVSS severity6.5
Medium
EPSS probability8.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Xen hypervisor allows guest OS users to crash an x86 host through a crafted HVM or PVH hypercall continuation. During continuation handling, 32-bit register translation preserves attacker-controlled high halves, while a later sanity check assumes those halves are clear and triggers a hypervisor consistency failure. Only HVM or PVH guests on x86 systems can reach the flaw; the resulting crash interrupts every guest on the host.

The record

CVE
CVE-2023-46842
Published
May 16, 2024
Updated
Nov 4, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-843, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 16, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 4, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/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.

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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-843Access of Resource Using Incompatible Type ('Type Confusion')
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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