CVE-2023-53990

Kernel memory corruption via unlocked deferred-close list

Published Dec 24, 2025 · Updated Dec 24, 2025

Race condition in the Linux kernel SMB3 client allows local users to corrupt kernel memory through a mounted CIFS share. The cifs_del_deferred_close function deletes and frees entries from the deferred-close list without holding deferred_lock, allowing concurrent open, close, unlink, or rename operations to corrupt the list. An unprivileged local user needs access to an already-mounted CIFS share; successful triggering can expose or overwrite kernel memory or repeatedly panic the host.

CVSS severity7.8
High
EPSS probability0.15%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in the Linux kernel SMB3 client allows local users to corrupt kernel memory through a mounted CIFS share. The cifs_del_deferred_close function deletes and frees entries from the deferred-close list without holding deferred_lock, allowing concurrent open, close, unlink, or rename operations to corrupt the list. An unprivileged local user needs access to an already-mounted CIFS share; successful triggering can expose or overwrite kernel memory or repeatedly panic the host.

The record

CVE
CVE-2023-53990
Published
Dec 24, 2025
Updated
Dec 24, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 24, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 24, 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=6.0
  2. Affected versionversion=60b6d38add7b9c17d6e5d49ee8e930ea1a5650c5
  3. Affected versionversion=860efae127888ae535bc4eda1b7f27642727c69e <0f87e18203bd30f71eb1a65259e28e291b6cc43a
  4. Affected versionversion=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <32a046ccaeea6c19965c04a4c521e703f6607924
  5. Affected versionversion=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <3aa9d065b0685b4e6052f3f2a2462966fdc44fd2
  6. Affected versionversion=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <ab9ddc87a9055c4bebd6524d5d761d605d52e557
  7. Affected versionversion=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <cb36365dac25d546ca4af0eb22acb43c9b4ddfdf

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.0; version=60b6d38add7b9c17d6e5d49ee8e930ea1a5650c5; version=860efae127888ae535bc4eda1b7f27642727c69e <0f87e18203bd30f71eb1a65259e28e291b6cc43a; version=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <32a046ccaeea6c19965c04a4c521e703f6607924; version=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <3aa9d065b0685b4e6052f3f2a2462966fdc44fd2; version=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <ab9ddc87a9055c4bebd6524d5d761d605d52e557; version=ca08d0eac020d48a3141dbec0a3cf64fbdb17cde <cb36365dac25d546ca4af0eb22acb43c9b4ddfdf

Published CVSS scores

7.8LinuxCVSS: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

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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