CVE intelligence and bounded remediation

CVE-2026-53228 — Linux Linux Kernel security vulnerability

Critical CVSS 9.8

In the Linux kernel, the following vulnerability has been resolved: ipv6: sit: reload inner IPv6 header after GSO offloads ipip6_tunnel_xmit() caches the inner IPv6 header pointer at function entry and continues using it after iptunnel_handle_offloads(). For GSO skbs, iptunnel_handle_offloads() calls skb_header_unclone(). When the skb header is cloned, skb_header_unclone() can call pskb_expand_head(), which may move the skb head. The pskb_expand_head() contract requires pointers into the skb header to be reloaded after the call. If the later skb_realloc_headroom() branch is not taken, SIT uses the stale iph6 pointer to read the inner hop limit and DS field. That can read from a freed skb head after the old head's remaining clone is released. Reload iph6 after the offload helper succeeds and before subsequent reads from the inner IPv6 header. Keep the existing reload after skb_realloc_headroom(), since that branch can also replace the skb.

Severity
Critical
CVSS
9.8 (3.1)
Published
2026-06-25
CISA KEV
Not currently listed
Ecosystem
linux/kernel

Affected products

  • linux / linux_kernel
  • linux / linux_kernel / 7.1

Showing 2 representative product identities from 14 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

General vulnerability remediation

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Confirm the affected component, deployment paths, reachable interfaces, and enabled features from inventories and configuration, without probing production destructively.
  • Compare the advisory's affected conditions with the repository lockfiles, build manifests, artifacts, and runtime inventory.
  • Identify data sensitivity, trust boundaries, and privilege level for every confirmed affected deployment.

Remediate safely

  • Apply a vendor-supported fix or remove the affected component or feature; record the selected change and its source in the repository.
  • Update direct and transitive dependency locks, generated artifacts, deployment manifests, and asset inventories together.
  • Add a regression test for the documented unsafe condition using inert inputs and preserve rollback instructions.

Authoritative sources

Complete CVE record and remediation plan

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