CVE-2026-63994 — tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]()
In the Linux kernel, the following vulnerability has been resolved: tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]() Sashiko found that iptunne…
Published: 2026-07-19 · CVSS: 9.8 · CVSS 3.1
In the Linux kernel, the following vulnerability has been resolved: tunnels: load network headers after skb_cow() in iptunnel_pmtud_build_icmp[v6]() Sashiko found that iptunnel_pmtud_build_icmp() and iptunnel_pmtud_build_icmpv6() were caching ip_hdr() and ipv6_hdr() before an skb_cow() call which can reallocate skb->head. Fix this possible UAF by initializing the local variables after the skb_cow() call. Remove skb_reset_network_header() calls which were not needed.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7