CVE-2023-52751

Kernel crash via cached-directory lease-break race

Published May 21, 2024 · Updated Aug 5, 2026

Use-after-free in the Linux SMB client in 6.1 through 6.5.12 and 6.6 through 6.6.2 allows local users to crash the kernel. A lease break can clear has_lease while open_cached_dir() creates a cached directory handle, causing the last cfid reference to be dropped before smb2_query_info_compound() reads it. The race requires access to an already-mounted CIFS share and concurrent filesystem operations; a crash interrupts the host.

CVSS severity7.8
High
EPSS probability0.24%
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 SMB client in 6.1 through 6.5.12 and 6.6 through 6.6.2 allows local users to crash the kernel. A lease break can clear has_lease while open_cached_dir() creates a cached directory handle, causing the last cfid reference to be dropped before smb2_query_info_compound() reads it. The race requires access to an already-mounted CIFS share and concurrent filesystem operations; a crash interrupts the host.

The record

CVE
CVE-2023-52751
Published
May 21, 2024
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1499
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=6.1
  2. Affected versionversion=ebe98f1447bbccf8228335c62d86af02a0ed23f7 <5c86919455c1edec99ebd3338ad213b59271a71b
  3. Affected versionversion=ebe98f1447bbccf8228335c62d86af02a0ed23f7 <6db94d08359c43f2c8fe372811cdee04564a41b9
  4. Affected versionversion=ebe98f1447bbccf8228335c62d86af02a0ed23f7 <93877b9afc2994c89362007aac480a7b150f386f

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.1; version=ebe98f1447bbccf8228335c62d86af02a0ed23f7 <5c86919455c1edec99ebd3338ad213b59271a71b; version=ebe98f1447bbccf8228335c62d86af02a0ed23f7 <6db94d08359c43f2c8fe372811cdee04564a41b9; version=ebe98f1447bbccf8228335c62d86af02a0ed23f7 <93877b9afc2994c89362007aac480a7b150f386f

Published CVSS scores

7.8NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Linux kernel CNACVSS: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 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
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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