What’s Vulnerable › Vulnerabilities

CVE-2026-72417: netfilter: flowtable: Validate iph->ihl in nf_flow_ip4_tunnel_proto()

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.6% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-15 · updated 2026-08-17

Description

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.

Affected products

• Linux kernel: 6.19 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/025a41e76b51fbc7b8eaa5bacbaa9621d00e6aa7
• https://git.kernel.org/stable/c/84460b644329e25809b4a6d9279d6359d7fd8ebc

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