VDB-235738 · CVE-2023-3866 · WID-SEC-2025-1858

Linux Kernel ksmbd null pointer dereference

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5.6	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel. It has been declared as critical. This affects an unknown function of the component ksmbd. Executing a manipulation can lead to null pointer dereference. This vulnerability appears as CVE-2023-3866. The attack may be performed from remote. There is no available exploit. A patch should be applied to remediate this issue.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel (Operating System) (version now known). This vulnerability affects some unknown processing of the component ksmbd. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate session id and tree id in the compound request This patch validate session id and tree id in compound request. If first operation in the compound is SMB2 ECHO request, ksmbd bypass session and tree validation. So work->sess and work->tcon could be NULL. If secound request in the compound access work->sess or tcon, It cause NULL pointer dereferecing error.

The weakness was presented 07/29/2023. The advisory is available at lore.kernel.org. This vulnerability was named CVE-2023-3866 since 07/24/2023. The technical details are unknown and an exploit is not available.

Applying a patch is able to eliminate this problem. The bugfix is ready for download at lore.kernel.org.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1858). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

Debian Linux
Amazon Linux 2
Red Hat Enterprise Linux
Ubuntu Linux
SUSE Linux
Oracle Linux
SUSE openSUSE
RESF Rocky Linux
Dell Avamar
Open Source Linux Kernel
Dell NetWorker
Dell Secure Connect Gateway
IBM QRadar SIEM
IBM Security Verify Access

Productinfo

Type

Operating System

Vendor

Linux

Name

Kernel

License

open-source

Website

Vendor: https://www.kernel.org/

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.6

VulDB Base Score: 5.9
VulDB Temp Score: 5.7
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
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💳	💳	💳	💳	💳	💳
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Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

0-Day Time: 🔍

Patch: lore.kernel.org

Timelineinfo

07/24/2023 🔍
07/29/2023 +5 days 🔍
07/29/2023 +0 days 🔍
01/30/2026 +916 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: lore.kernel.org
Status: Confirmed

CVE: CVE-2023-3866 (🔍)
GCVE (CVE): GCVE-0-2023-3866
GCVE (VulDB): GCVE-100-235738
CERT Bund: WID-SEC-2025-1858 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 07/29/2023 06:49
Updated: 01/30/2026 15:34
Changes: 07/29/2023 06:49 (39), 08/16/2025 16:54 (16), 08/18/2025 12:40 (7), 09/28/2025 06:40 (1), 10/02/2025 17:51 (1), 10/12/2025 16:40 (1), 11/01/2025 18:43 (1), 11/18/2025 10:37 (1), 11/19/2025 02:42 (12), 01/30/2026 15:34 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.