What is CVE-2026-72137?

CVE-2026-72137 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, affecting Linux kernel versions from 6.11 onward and patched in 6.12.101, 6.18.40, 7.1.5 and others. CVE-2026-72137 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-72137?

CVE-2026-72137 has a CVSS score of 9.8 out of 10, rated Critical severity. The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-72137?

Yes, CVE-2026-72137 has been patched. Fixed versions include 6.12.101, 6.18.40, 7.1.5 and others. If you are running Linux kernel 6.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-72137 actively exploited?

CVE-2026-72137 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-72137

Critical

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.

Package Linux Kernel

Published 2026-08-15

Last modified 2026-08-17

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

9.8

out of 10

Critical

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 6.11 and later are affected. Fixed in 6.12.101, 6.18.40, 7.1.5, 7.2 and their respective stable series.

Affected from

≥ 6.11

Fixed in

✓ 6.12.101 6.12.x ✓ 6.18.40 6.18.x ✓ 7.1.5 7.1.x ✓ 7.2

References

4 total

Details

CVE ID CVE-2026-72137

Severity Critical

CVSS score 9.8 / 10

CVSS version 3.1

Published 2026-08-15

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-72137?

CVE-2026-72137 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 . It affects Linux kernel versions from 6.11 onward and has been patched in 6.12.101, 6.18.40, 7.1.5 and others. CVE-2026-72137 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-72137?

CVE-2026-72137 has a CVSS score of 9.8 out of 10, rated Critical severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-72137?

Yes. CVE-2026-72137 has been patched. Fixed versions include 6.12.101, 6.18.40, 7.1.5 and others. If you are running Linux kernel 6.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-72137 actively exploited?

No. CVE-2026-72137 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.