Linux Kernel up to 6.17.2 ocfs2 user_cluster_connect double free

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.15.194/6.1.155/6.6.111/6.12.52/6.17.2 and classified as critical. This affects the function user_cluster_connect of the component ocfs2. Executing a manipulation can lead to double free. This vulnerability is registered as CVE-2025-40055. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 5.15.194/6.1.155/6.6.111/6.12.52/6.17.2 and classified as critical. This vulnerability affects the function user_cluster_connect of the component ocfs2. The manipulation with an unknown input leads to a double free vulnerability. The CWE definition for the vulnerability is CWE-415. The product calls free() twice on the same memory address, potentially leading to modification of unexpected memory locations. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix double free in user_cluster_connect() user_cluster_disconnect() frees "conn->cc_private" which is "lc" but then the error handling frees "lc" a second time. Set "lc" to NULL on this path to avoid a double free.

The advisory is available at git.kernel.org. This vulnerability was named CVE-2025-40055 since 04/16/2025. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 05/20/2026).

The vulnerability scanner Nessus provides a plugin with the ID 271875 (Linux Distros Unpatched Vulnerability : CVE-2025-40055), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.195, 6.1.156, 6.6.112, 6.12.53, 6.17.3 or 6.18-rc1 eliminates this vulnerability. Applying the patch 827c8efa0d1afe817b90f3618afff552e88348d2/bfe011297ddd2d0cd64752978baaa0c04cd20573/7e76fe9dfadbc00364d7523d5a109e9d3e4a7db2/694d5b401036a614f8080085a9de6f86ff0742dc/892f41e12c8689130d552a9eb2b77bafd26484ab/8f45f089337d924db24397f55697cda0e6960516 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 (271875) and CERT Bund (WID-SEC-2025-2431). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Google Container-Optimized OS
  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • IBM QRadar SIEM
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure
  • Dell NetWorker
  • Dell ECS

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Double free
CWE: CWE-415 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 271875
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-40055

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.195/6.1.156/6.6.112/6.12.53/6.17.3/6.18-rc1
Patch: 827c8efa0d1afe817b90f3618afff552e88348d2/bfe011297ddd2d0cd64752978baaa0c04cd20573/7e76fe9dfadbc00364d7523d5a109e9d3e4a7db2/694d5b401036a614f8080085a9de6f86ff0742dc/892f41e12c8689130d552a9eb2b77bafd26484ab/8f45f089337d924db24397f55697cda0e6960516

Timelineinfo

04/16/2025 CVE reserved
10/28/2025 +195 days Advisory disclosed
10/28/2025 +0 days VulDB entry created
05/20/2026 +204 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40055 (🔒)
GCVE (CVE): GCVE-0-2025-40055
GCVE (VulDB): GCVE-100-330250
CERT Bund: WID-SEC-2025-2431 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 10/28/2025 14:42
Updated: 05/20/2026 03:46
Changes: 10/28/2025 14:42 (59), 10/30/2025 05:51 (7), 10/30/2025 13:58 (2), 10/31/2025 10:08 (1), 11/24/2025 20:25 (1), 12/22/2025 01:42 (1), 02/08/2026 17:31 (1), 02/15/2026 20:05 (1), 05/20/2026 03:46 (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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