CVE-2023-52837

Local privilege escalation via NBD teardown race

Published May 21, 2024 · Updated Aug 5, 2026

Use-after-free in the Linux kernel NBD subsystem allows local users to escalate privileges by racing device teardown against opening an NBD device. nbd_dev_remove frees the nbd_device while blk_cleanup_disk leaves disk->private_data intact, so a concurrent nbd_open dereferences stale private data. Exploitation requires access to an existing NBD device node configured for teardown on disconnect; the race can also trigger a kernel panic.

CVSS severity7.8
High
EPSS probability0.25%
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 NBD subsystem allows local users to escalate privileges by racing device teardown against opening an NBD device. nbd_dev_remove frees the nbd_device while blk_cleanup_disk leaves disk->private_data intact, so a concurrent nbd_open dereferences stale private data. Exploitation requires access to an existing NBD device node configured for teardown on disconnect; the race can also trigger a kernel panic.

The record

CVE
CVE-2023-52837
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2024CVE 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=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <327462725b0f759f093788dfbcb2f1fd132f956b
  2. Affected versionversion=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <4e9b3ec84dc97909876641dad14e0a2300d6c2a3
  3. Affected versionversion=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <56bd7901b5e9dbc9112036ea615ebcba1565fafe
  4. Affected versionversion=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <879947f4180bc6e83af64eb0515e0cf57fce15db
  5. Affected versionversion=5.14

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <327462725b0f759f093788dfbcb2f1fd132f956b; version=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <4e9b3ec84dc97909876641dad14e0a2300d6c2a3; version=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <56bd7901b5e9dbc9112036ea615ebcba1565fafe; version=4af5f2e0301311f88c420fcfc5f3c8611ade20ac <879947f4180bc6e83af64eb0515e0cf57fce15db; version=5.14

Published CVSS scores

7.8NIST NVDCVSS: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

CWE-416Use After Free
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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