CVE-2023-54076

System crash via DFS session use-after-free

Published Dec 24, 2025 · Updated Dec 24, 2025

Use-after-free in the Linux kernel SMB client in 6.4 through 6.4.6 allows local users to crash the system during DFS session handling. The DFS and SMB2 transport paths fail to take active references to a session and its dfs_root_ses before cifs_put_smb_ses releases them. Reaching the flaw requires a mounted SMB share with DFS referrals; the documented consequence is a kernel use-after-free that can crash the system, while public sources do not establish code execution.

CVSS severity9.8
Critical
EPSS probability0.44%
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 SMB client in 6.4 through 6.4.6 allows local users to crash the system during DFS session handling. The DFS and SMB2 transport paths fail to take active references to a session and its dfs_root_ses before cifs_put_smb_ses releases them. Reaching the flaw requires a mounted SMB share with DFS referrals; the documented consequence is a kernel use-after-free that can crash the system, while public sources do not establish code execution.

The record

CVE
CVE-2023-54076
Published
Dec 24, 2025
Updated
Dec 24, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-911, 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.4
  2. Affected versionversion=8e3554150d6c80a84b3cb046615d1a0e943811dc <bf99f6be2d20146942bce6f9e90a0ceef12cbc1e
  3. Affected versionversion=8e3554150d6c80a84b3cb046615d1a0e943811dc <eb382196e6f6e05cfafdab797840e5a96c6e7bf0
  4. Affected versionversion=c082c3be0f96e759ff2e361d929832fda0b93851
  5. Affected versionversion=f30d226bcc9f0e2d97b4a6e94c43a28148fbeab6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.4; version=8e3554150d6c80a84b3cb046615d1a0e943811dc <bf99f6be2d20146942bce6f9e90a0ceef12cbc1e; version=8e3554150d6c80a84b3cb046615d1a0e943811dc <eb382196e6f6e05cfafdab797840e5a96c6e7bf0; version=c082c3be0f96e759ff2e361d929832fda0b93851; version=f30d226bcc9f0e2d97b4a6e94c43a28148fbeab6

Published CVSS scores

9.8CVE.orgCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
5.5Red HatCVSS:3.1/AV:L/AC:L/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 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-911Improper Update of Reference Count
T1499.004Application or System Exploitation

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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