Linux Kernel up to 6.16.8 ksmbd recv_done data_offset/data_length out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Linux Kernel up to 5.15.193/6.1.153/6.6.107/6.12.48/6.16.8. This issue affects the function recv_done of the component ksmbd. Executing a manipulation of the argument data_offset/data_length can lead to out-of-bounds. The identification of this vulnerability is CVE-2025-39943. There is no exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.15.193/6.1.153/6.6.107/6.12.48/6.16.8. This vulnerability affects the function recv_done of the component ksmbd. The manipulation of the argument data_offset/data_length with an unknown input leads to a out-of-bounds vulnerability. The CWE definition for the vulnerability is CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ksmbd: smbdirect: validate data_offset and data_length field of smb_direct_data_transfer If data_offset and data_length of smb_direct_data_transfer struct are invalid, out of bounds issue could happen. This patch validate data_offset and data_length field in recv_done.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2025-39943 since 04/16/2025. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 269456 (Linux Distros Unpatched Vulnerability : CVE-2025-39943), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.194, 6.1.154, 6.6.108, 6.12.49 or 6.16.9 eliminates this vulnerability. Applying the patch 773fddf976d282ef059c36c575ddb81567acd6bc/bdaab5c6538e250a9654127e688ecbbeb6f771d5/eb0378dde086363046ed3d7db7f126fc3f76fd70/8be498fcbd5b07272f560b45981d4b9e5a2ad885/529b121b00a6ee3c88fb3c01b443b2b81f686d48/5282491fc49d5614ac6ddcd012e5743eecb6a67c is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (269456) and CERT Bund (WID-SEC-2025-2194). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • NetApp ActiveIQ Unified Manager
  • IBM QRadar SIEM
  • Dell NetWorker

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.1
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 269456
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-39943

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.194/6.1.154/6.6.108/6.12.49/6.16.9
Patch: 773fddf976d282ef059c36c575ddb81567acd6bc/bdaab5c6538e250a9654127e688ecbbeb6f771d5/eb0378dde086363046ed3d7db7f126fc3f76fd70/8be498fcbd5b07272f560b45981d4b9e5a2ad885/529b121b00a6ee3c88fb3c01b443b2b81f686d48/5282491fc49d5614ac6ddcd012e5743eecb6a67c

Timelineinfo

04/16/2025 CVE reserved
10/04/2025 +171 days Advisory disclosed
10/04/2025 +0 days VulDB entry created
04/28/2026 +206 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39943 (🔒)
GCVE (CVE): GCVE-0-2025-39943
GCVE (VulDB): GCVE-100-327034
CERT Bund: WID-SEC-2025-2194 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 10/04/2025 11:33
Updated: 04/28/2026 06:27
Changes: 10/04/2025 11:33 (60), 10/08/2025 17:41 (2), 11/24/2025 02:44 (7), 12/27/2025 00:10 (1), 01/27/2026 21:45 (11), 04/28/2026 06:27 (1)
Complete: 🔍
Cache ID: 216::103

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

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