Linux Kernel up to 6.12.53/6.17.3 path_put privilege escalation

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.53/6.17.3. It has been classified as critical. Affected by this issue is the function path_put. The manipulation leads to an unknown weakness. This vulnerability is uniquely identified as CVE-2025-40203. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.53/6.17.3 and classified as critical. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: listmount: don't call path_put() under namespace semaphore Massage listmount() and make sure we don't call path_put() under the namespace semaphore. If we put the last reference we're fscked.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2025-40203 since 04/16/2025. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 02/07/2026).

The vulnerability scanner Nessus provides a plugin with the ID 275350 (Linux Distros Unpatched Vulnerability : CVE-2025-40203), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.54, 6.17.4 or 6.18-rc1 eliminates this vulnerability. Applying the patch 659874b7ee4976ad9ce476e07fd36bc67b3537f1/9c80da26fda2fdcaac7f92b5908875b3108830ff/c1f86d0ac322c7e77f6f8dbd216c65d39358ffc0 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 (275350) and CERT Bund (WID-SEC-2025-2595). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Google Container-Optimized OS
• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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