{"id":"CVE-2026-72137","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-72137","summary":"xfrm: nat_keepalive: avoid double free on send error","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: nat_keepalive: avoid double free on send error\n\nnat_keepalive_send() frees the keepalive skb whenever the IPv4 or IPv6\nsend helper reports an error.\n\nThat cleanup is only correct before the skb is handed to the output\npath. Once ip_build_and_send_pkt() or ip6_xmit() takes ownership, the\nnetworking stack may already have consumed the skb before returning an\nerror, so freeing it again is unsafe.\n\nHandle the pre-handoff failure cases inside nat_keepalive_send_ipv4()\nand nat_keepalive_send_ipv6(), where the caller still owns the skb, and\nkeep nat_keepalive_send() responsible only for family dispatch and the\nunsupported-family cleanup path.","published":"2026-08-15T05:53:11.812Z","modified":"2026-08-18T03:56:37.517403131Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.12.101"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/226f4a490d1a938fc838d8f8c46a4eca864c0d78"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5b0c4c916f202b8fd13d12afb6af62b385622f81"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a8a7e6a9ff8a4c1f067694ddbd44be67fdf36693"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d0a4dc7efa825bce60a8da8f7d43c864a159abde"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72137.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72137"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:37.517403131Z"}}