Vulnerability intelligence

CVE-2026-72137

In the Linux kernel, the following vulnerability has been resolved: xfrm: nat_keepalive: avoid double free on send error nat_keepalive_send() frees the keepalive skb whenever the IPv4 or IPv6 send helper reports an error. That cleanup is only correct before the skb is handed to the output path. Once ip_build_and_send_pkt() or ip6_xmit() takes ownership, the networking stack may already have consumed the skb before returning an error, so freeing it again is unsafe. Handle the pre-handoff failure cases inside nat_keepalive_send_ipv4() and nat_keepalive_send_ipv6(), where the caller still owns the skb, and keep nat_keepalive_send() responsible only for family dispatch and the unsupported-family cleanup path.

CVSS Score

9.8

Critical

EPSS — Exploit Probability

0.7%

Riskier than 51% of all CVEs · checked 2026-10-10

Exploitation

Not in CISA KEV

KEV does not include every exploited vulnerability

Remediation

unknown

Check vendor advisories