CVE-2023-1859

Guest crash via unsynchronized 9P teardown

Published May 17, 2023 · Updated Mar 18, 2025

Use-after-free in the Linux kernel before 6.3-rc7 allows local users to crash a Xen guest through a 9P frontend removal race. xen_9pfs_front_free releases frontend private state without first synchronizing scheduled ring work, so p9_xen_response can dereference priv->client after priv is freed. Reachability requires a Xen guest with the 9P frontend present and response work racing device teardown; reported consequences are limited to guest crash or guest-kernel memory exposure.

CVSS severity4.7
Medium
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the Linux kernel before 6.3-rc7 allows local users to crash a Xen guest through a 9P frontend removal race. xen_9pfs_front_free releases frontend private state without first synchronizing scheduled ring work, so p9_xen_response can dereference priv->client after priv is freed. Reachability requires a Xen guest with the 9P frontend present and response work racing device teardown; reported consequences are limited to guest crash or guest-kernel memory exposure.

The record

CVE
CVE-2023-1859
Published
May 17, 2023
Updated
Mar 18, 2025
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-416
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 18, 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=Kernel version prior to 6.3-rc7

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=Kernel version prior to 6.3-rc7

Published CVSS scores

1.9SUSECVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:L
4.7NIST NVDCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
4.7CISA-ADPCVSS:3.1/AV:L/AC:H/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.

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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-416Use After Free

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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