CVE-2026-72442

netfilter: flowtable: fix and simplify IP6IP6 tunnel handling

State
Published
Severity
9.8 Critical
Published
Aug 15, 2026
Updated
Aug 17, 2026
Reserved
Aug 9, 2026

Read the record on cve.org

Description

In the Linux kernel, the following vulnerability has been resolved:

netfilter: flowtable: fix and simplify IP6IP6 tunnel handling

Fix nf_flow_ip6_tunnel_proto() to use pskb_may_pull() instead of skb_header_pointer() to ensure the outer IPv6 header is in the skb headroom, which is required for subsequent packet processing. Move ctx->offset update inside the IPPROTO_IPV6 conditional block since it should only be adjusted when an IP6IP6 tunnel is actually detected. Simplify the rx path by removing ipv6_skip_exthdr() and checking ip6h->nexthdr directly, as the flowtable fast path only handles simple IP6IP6 encapsulation without extension headers. Drop the tunnel encapsulation limit destination option support from the tx path to match, since the rx path no longer handles extension headers. Remove the encap_limit parameter from nf_flow_offload_ipv6_forward(), nf_flow_tunnel_ip6ip6_push() and nf_flow_tunnel_v6_push(), along with the ipv6_tel_txoption struct and related headroom/MTU adjustments.

Scores

CVSSScoreVectorSource
3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • d98103575dcdd3a730e0901ab457791a9ac6930c to before 7f8d816a9aa2729d270418f00c9ef5e85bfc1b31Affected
  • d98103575dcdd3a730e0901ab457791a9ac6930c to before f4c2d8668d85ed125985da663c824a9c25498257Affected
LinuxLinux
  • 7.0Affected
  • before 7.0Not affected
  • 7.1.5 through 7.1.*Not affected
  • 7.2 and laterNot affected

References

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