Linux Kernel xsk xsk_tx_metadata_request toctou

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel. This affects the function xsk_tx_metadata_request of the component xsk. Performing a manipulation results in toctou. This vulnerability was named CVE-2026-74707. The attack needs to be approached locally. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Linux Kernel (affected version not known). This affects the function xsk_tx_metadata_request of the component xsk. The manipulation with an unknown input leads to a toctou vulnerability. CWE is classifying the issue as CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. 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: xsk: validate metadata when processing requests The zero-copy path validates TX metadata while obtaining the descriptor context, then reads it again later when preparing the hardware request. User space can change the metadata between those operations and bypass the original validation. Validate the metadata in xsk_tx_metadata_request() and use the resulting flags snapshot for every feature check. Read request fields once so all zero-copy drivers process only values observed after successful validation.

The advisory is shared at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-74707 since 08/15/2026. The exploitability is told to be easy. An attack has to be approached locally. Additional levels of successful authentication are necessary for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/22/2026).

Applying the patch 5fd121971912dee2f5af1efec64462ac722deb17/0cc7aa6e0d19027fdd42e6fbd156267ac1e3bbba/849b1664dbda1cf6c63e0fd4f9dec23782b8c851 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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