Riskcovery

CVE-2026-72137

xfrm: nat_keepalive: avoid double free on send error

State
Published
Severity
9.8 Critical
Published
Aug 15, 2026
Updated
Aug 17, 2026
Reserved
Aug 9, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.19.8 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae to before d0a4dc7efa825bce60a8da8f7d43c864a159abdeAffected
  • f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae to before 5b0c4c916f202b8fd13d12afb6af62b385622f81Affected
  • f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae to before a8a7e6a9ff8a4c1f067694ddbd44be67fdf36693Affected
  • f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae to before 226f4a490d1a938fc838d8f8c46a4eca864c0d78Affected
LinuxLinux
  • 6.11Affected
  • before 6.11Not affected
  • 6.12.101 through 6.12.*Not affected
  • 6.18.40 through 6.18.*Not affected
  • 7.1.5 through 7.1.*Not affected
  • 7.2 and laterNot affected

References

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.