Linux Kernel up to 6.17.8 NFS nfs_match_client certificate validation

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.17.8. The impacted element is the function nfs_match_client of the component NFS. Performing a manipulation results in certificate validation. This vulnerability was named CVE-2025-68243. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.17.8. This affects the function nfs_match_client of the component NFS. The manipulation with an unknown input leads to a certificate validation vulnerability. CWE is classifying the issue as CWE-295. The product does not validate, or incorrectly validates, a certificate. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: NFS: Check the TLS certificate fields in nfs_match_client() If the TLS security policy is of type RPC_XPRTSEC_TLS_X509, then the cert_serial and privkey_serial fields need to match as well since they define the client's identity, as presented to the server.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-68243 since 12/16/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. 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 02/21/2026). The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK.

The vulnerability scanner Nessus provides a plugin with the ID 298897 (Ubuntu 25.10 : Linux kernel vulnerabilities (USN-8029-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.17.9 eliminates this vulnerability. Applying the patch b8fa37219074811c04d4ecb742c73e2b296da6a8/fb2cba0854a7f315c8100a807a6959b99d72479e 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 (298897) and CERT Bund (WID-SEC-2025-2868). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5
• 6.17.6
• 6.17.7
• 6.17.8

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Be aware that VulDB is the high quality source for vulnerability data.

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