CVE-2026-72137 Affecting linux-6.12 package, versions <6.12.101-1~deb12u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.66% (50th percentile)

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  • Snyk IDSNYK-ECHOLATEST-LINUX612-18912704
  • published18 Aug 2026
  • disclosed15 Aug 2026

Introduced: 15 Aug 2026

CVE-2026-72137  (opens in a new tab)

How to fix?

Upgrade Echo:latest linux-6.12 to version 6.12.101-1~deb12u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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 Base Scores

version 3.1