CVE-2026-63992

In the Linux kernel, the following vulnerability has been resolved: tunnels: do not assume transport header in iptunnel_pmtud_check_icmp() In some cases, iptunnel_pmtud_check_icmp() can be called while skb transport header is not set. This triggers an out-of-bound access, because (typeof(skb->transport_header))~0U is 65535. Access the icmp header based on IPv4 network header, after making sure icmp->type is present in skb linear part. Note that iptunnel_pmtud_check_icmpv6()) is fine.

Score
CVSS 3.1 9.1 Critical
Status
Modified - 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-07-19
Last modified
2026-10-19
Weaknesses
CWE-125

Affected products

References