Linux Kernel flowtable nf_flow_ip4_tunnel_proto memory corruption

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Linux Kernel. This issue affects the function nf_flow_ip4_tunnel_proto of the component flowtable. This manipulation causes memory corruption. This vulnerability is handled as CVE-2026-72417. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel (affected version unknown). It has been declared as very critical. Affected by this vulnerability is the function nf_flow_ip4_tunnel_proto of the component flowtable. The manipulation with an unknown input leads to a memory corruption vulnerability. The CWE definition for the vulnerability is CWE-119. The product performs operations on a memory buffer, but it can read from or write to a memory location that is outside of the intended boundary of the buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: Validate iph->ihl in nf_flow_ip4_tunnel_proto() Add sanity check for iph->ihl field in nf_flow_ip4_tunnel_proto() before using it to compute the header size, avoiding out-of-bounds access with malformed IP headers. While at it, use iph->protocol instead of the hardcoded IPPROTO_IPIP constant when setting ctx->tun.proto and reference ctx->tun.hdr_size when updating ctx->offset.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-72417 since 08/09/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/15/2026).

Applying the patch 84460b644329e25809b4a6d9279d6359d7fd8ebc is able to eliminate this problem.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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