CVE-2023-53273

Guest crash via premature VMBus relid lookup

Published Sep 16, 2025 · Updated Sep 16, 2025

A NULL pointer dereference in the Linux kernel allows local users to crash a Hyper-V guest during second-kernel VMBus initialization. relid2channel() dereferences the VMBus channel array without checking whether vmbus_connect() has allocated it when resolving an interrupt relid. The condition requires kdump or kexec to boot a second kernel with stale host relids and a VMBus interrupt to arrive before connection setup completes or after it fails.

CVSS severity5.5
Medium
EPSS probability0.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A NULL pointer dereference in the Linux kernel allows local users to crash a Hyper-V guest during second-kernel VMBus initialization. relid2channel() dereferences the VMBus channel array without checking whether vmbus_connect() has allocated it when resolving an interrupt relid. The condition requires kdump or kexec to boot a second kernel with stale host relids and a VMBus interrupt to arrive before connection setup completes or after it fails.

The record

CVE
CVE-2023-53273
Published
Sep 16, 2025
Updated
Sep 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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?

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

  1. Affected versionversion=5.8
  2. Affected versionversion=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <176c6b4889195fbe7016d9401175b48c5c9edf68
  3. Affected versionversion=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <1eb65c8687316c65140b48fad27133d583178e15
  4. Affected versionversion=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <8c3f0ae5435fd20bb1e3a8308488aa6ac33151ee
  5. Affected versionversion=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <a5c44f3446a0565139b7d8abc78f58b86c398123
  6. Affected versionversion=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <c373e49fbb87aa177819866ed9194ebc5414dfd6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.8; version=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <176c6b4889195fbe7016d9401175b48c5c9edf68; version=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <1eb65c8687316c65140b48fad27133d583178e15; version=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <8c3f0ae5435fd20bb1e3a8308488aa6ac33151ee; version=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <a5c44f3446a0565139b7d8abc78f58b86c398123; version=8b6a877c060ed6b86878fe66c7c6493a6054cf23 <c373e49fbb87aa177819866ed9194ebc5414dfd6

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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.

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-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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