CVE-2026-72137xfrm: nat_keepalive: avoid double free on send error
Updated under an hour ago ()
Does this affect you?
It affects Linux. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
Do this next
Free account, 1 product
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
- 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Aug 17, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae before d0a4dc7efa825bce60a8da8f7d43c864a159abde; from f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae before 5b0c4c916f202b8fd13d12afb6af62b385622f81; from f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae before a8a7e6a9ff8a4c1f067694ddbd44be67fdf36693; from f531d13bdfe3f4f084aaa8acae2cb0f02295f5ae before 226f4a490d1a938fc838d8f8c46a4eca864c0d78 | CNA record |
References
- https://git.kernel.org/stable/c/d0a4dc7efa825bce60a8da8f7d43c864a159abde
- https://git.kernel.org/stable/c/5b0c4c916f202b8fd13d12afb6af62b385622f81
- https://git.kernel.org/stable/c/a8a7e6a9ff8a4c1f067694ddbd44be67fdf36693
- https://git.kernel.org/stable/c/226f4a490d1a938fc838d8f8c46a4eca864c0d78
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.