Linux Kernel flowtable input validation

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel. Affected by this vulnerability is an unknown functionality of the component flowtable. Performing a manipulation results in input validation. This vulnerability is known as CVE-2026-72246. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability classified as very critical has been found in Linux Kernel (the affected version is unknown). This affects an unknown code of the component flowtable. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. 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: netfilter: flowtable: use correct direction to set up tunnel route The layer 2 encapsulation and layer 3 tunnel information in the xmit path is taken from the other tuple, because the tunnel information that is included in the tuple for hashtable lookups is also used to perform the egress encapsulation in the transmit path. This patch uses the correct direction when setting up the tunnel, the original proposed patch to address this fix uses the reversed direction. While at it, remove the redundant check to call dst_release() to drop the reference on the dst that was obtained from the forward path, which is not useful in the direct xmit path unless tunneling is performed.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-72246 since 08/09/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/15/2026).

Applying the patch 392d033fd372268015bc5a54ba7c593ba44940d1 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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