CVE-2022-50227

Host crash via Xen timer reinitialization

Published Jun 18, 2025 · Updated Aug 5, 2026

A denial of service in Linux kernel 5.19 allows local users to crash the host by repeatedly configuring a KVM Xen vCPU timer. The KVM_XEN_VCPU_ATTR_TYPE_TIMER path calls kvm_xen_init_timer() on every attribute write, reinitializing an hrtimer that is already active instead of rejecting or reusing the existing timer. Exploitation requires low-privileged local access to the KVM vCPU ioctl path and an existing Xen timer; the observed result is an ODEBUG kernel crash.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A denial of service in Linux kernel 5.19 allows local users to crash the host by repeatedly configuring a KVM Xen vCPU timer. The KVM_XEN_VCPU_ATTR_TYPE_TIMER path calls kvm_xen_init_timer() on every attribute write, reinitializing an hrtimer that is already active instead of rejecting or reusing the existing timer. Exploitation requires low-privileged local access to the KVM vCPU ioctl path and an existing Xen timer; the observed result is an ODEBUG kernel crash.

The record

CVE
CVE-2022-50227
Published
Jun 18, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=5.19
  2. Affected versionversion=536395260582be7443b0b35b0bbb89ffe3947f62 <9a9b5771e930f408c3419799000f76a9abaf2278
  3. Affected versionversion=536395260582be7443b0b35b0bbb89ffe3947f62 <af735db31285fa699384c649be72a9f32ecbb665

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.19; version=536395260582be7443b0b35b0bbb89ffe3947f62 <9a9b5771e930f408c3419799000f76a9abaf2278; version=536395260582be7443b0b35b0bbb89ffe3947f62 <af735db31285fa699384c649be72a9f32ecbb665

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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