Is CVE-2025-21768 in the CISA KEV catalog?

No. CVE-2025-21768 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2025-21768?

CVE-2025-21768 has a CVSS v3 base score of 5.5 (MEDIUM).

What is the EPSS score for CVE-2025-21768?

CVE-2025-21768 has an EPSS score of 0.19% (9th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2025-21768?

Upgrade linux on debian 13 to 6.12.16-1 or later. Fixes are available for 140 affected products.

CVE & CISA-KEV Catalog

CVE-2025-21768

MEDIUM

5.5

CVSS v3

NVD

Description

In the Linux kernel, the following vulnerability has been resolved: net: ipv6: fix dst ref loops in rpl, seg6 and ioam6 lwtunnels Some lwtunnels have a dst cache for post-transformation dst. If the packet destination did not change we may end up recording a reference to the lwtunnel in its own cache, and the lwtunnel state will never be freed. Discovered by the ioam6.sh test, kmemleak was recently fixed to catch per-cpu memory leaks. I'm not sure if rpl and seg6 can actually hit this, but in principle I don't see why not.

CWE-401Missing Release of Memory (Memory Leak)

How to fix

Remediation Available

linuxDebian

Fixed in:6.12.16-1CVE-2025-21768

linuxUbuntu

Fixed in:6.8.0-78.78USN-7703-1

linux-awsUbuntu

Fixed in:6.8.0-1035.37USN-7703-1

linux-aws-6.8Ubuntu

Fixed in:6.8.0-1035.37~22.04.1USN-7703-2

linux-azureUbuntu

Fixed in:6.8.0-1034.39USN-7737-1

linux-azure-6.11Ubuntu

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-azure-6.8Ubuntu

Fixed in:6.8.0-1034.39~22.04.1USN-7737-1

linux-azure-nvidiaUbuntu

Fixed in:6.8.0-1022.23USN-7737-1

linux-gcpUbuntu

Fixed in:6.8.0-1036.38USN-7703-2

linux-gcp-6.11Ubuntu

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-gcp-6.8Ubuntu

Fixed in:6.8.0-1036.38~22.04.1USN-7703-2

linux-gkeUbuntu

Fixed in:6.8.0-1032.36USN-7703-4

linux-gkeopUbuntu

Fixed in:6.8.0-1019.21USN-7703-2

linux-hwe-6.11Ubuntu

Fixed in:6.11.0-26.26~24.04.1USN-7521-1

linux-hwe-6.8Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-ibmUbuntu

Fixed in:6.8.0-1033.33USN-7703-2

linux-ibm-6.8Ubuntu

Fixed in:6.8.0-1033.33~22.04.1USN-7703-2

linux-image-6.11.0-1014-lowlatencyUbuntu

Fixed in:6.11.0-1014.15~24.04.1USN-7521-3

linux-image-6.11.0-1014-lowlatency-64kUbuntu

Fixed in:6.11.0-1014.15~24.04.1USN-7521-3

linux-image-6.11.0-1015-azureUbuntu

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-6.11.0-1015-azure-fdeUbuntu

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-6.11.0-1015-gcpUbuntu

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-6.11.0-1015-gcp-64kUbuntu

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-6.11.0-1022-oemUbuntu

Fixed in:6.11.0-1022.22USN-7521-1

linux-image-6.11.0-26-genericUbuntu

Fixed in:6.11.0-26.26~24.04.1USN-7521-1

linux-image-6.11.0-26-generic-64kUbuntu

Fixed in:6.11.0-26.26~24.04.1USN-7521-1

linux-image-6.8.0-1019-gkeopUbuntu

Fixed in:6.8.0-1019.21USN-7703-2

linux-image-6.8.0-1022-azure-nvidiaUbuntu

Fixed in:6.8.0-1022.23USN-7737-1

linux-image-6.8.0-1032-gkeUbuntu

Fixed in:6.8.0-1032.36USN-7703-4

linux-image-6.8.0-1032-oracleUbuntu

Fixed in:6.8.0-1032.33~22.04.1USN-7703-3

Fixed in:6.8.0-1032.33USN-7703-3

linux-image-6.8.0-1032-oracle-64kUbuntu

Fixed in:6.8.0-1032.33~22.04.1USN-7703-3

Fixed in:6.8.0-1032.33USN-7703-3

linux-image-6.8.0-1033-ibmUbuntu

Fixed in:6.8.0-1033.33~22.04.1USN-7703-2

Fixed in:6.8.0-1033.33USN-7703-2

linux-image-6.8.0-1034-azureUbuntu

Fixed in:6.8.0-1034.39~22.04.1USN-7737-1

Fixed in:6.8.0-1034.39USN-7737-1

linux-image-6.8.0-1034-azure-fdeUbuntu

Fixed in:6.8.0-1034.39~22.04.1USN-7737-1

Fixed in:6.8.0-1034.39USN-7737-1

linux-image-6.8.0-1035-awsUbuntu

Fixed in:6.8.0-1035.37~22.04.1USN-7703-2

Fixed in:6.8.0-1035.37USN-7703-1

linux-image-6.8.0-1035-aws-64kUbuntu

Fixed in:6.8.0-1035.37~22.04.1USN-7703-2

Fixed in:6.8.0-1035.37USN-7703-1

linux-image-6.8.0-1035-nvidiaUbuntu

Fixed in:6.8.0-1035.38~22.04.1USN-7703-4

Fixed in:6.8.0-1035.38USN-7703-4

linux-image-6.8.0-1035-nvidia-64kUbuntu

Fixed in:6.8.0-1035.38~22.04.1USN-7703-4

Fixed in:6.8.0-1035.38USN-7703-4

linux-image-6.8.0-1035-nvidia-lowlatencyUbuntu

Fixed in:6.8.0-1035.38.1USN-7703-4

linux-image-6.8.0-1035-nvidia-lowlatency-64kUbuntu

Fixed in:6.8.0-1035.38.1USN-7703-4

linux-image-6.8.0-1035-raspiUbuntu

Fixed in:6.8.0-1035.39USN-7703-4

linux-image-6.8.0-1036-gcpUbuntu

Fixed in:6.8.0-1036.38~22.04.1USN-7703-2

Fixed in:6.8.0-1036.38USN-7703-2

linux-image-6.8.0-1036-gcp-64kUbuntu

Fixed in:6.8.0-1036.38~22.04.1USN-7703-2

Fixed in:6.8.0-1036.38USN-7703-2

linux-image-6.8.0-2028-raspi-realtimeUbuntu

Fixed in:6.8.0-2028.29USN-7719-1

linux-image-6.8.0-78-genericUbuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

Fixed in:6.8.0-78.78USN-7703-1

linux-image-6.8.0-78-generic-64kUbuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

Fixed in:6.8.0-78.78USN-7703-1

linux-image-6.8.0-78-lowlatencyUbuntu

Fixed in:6.8.0-78.78.1~22.04.1USN-7703-1

Fixed in:6.8.0-78.78.1USN-7703-1

linux-image-6.8.0-78-lowlatency-64kUbuntu

Fixed in:6.8.0-78.78.1~22.04.1USN-7703-1

Fixed in:6.8.0-78.78.1USN-7703-1

linux-image-6.8.1-1030-realtimeUbuntu

Fixed in:6.8.1-1030.31USN-7703-1

linux-image-awsUbuntu

Fixed in:6.8.0-1035.37~22.04.1USN-7703-2

linux-image-aws-6.8Ubuntu

Fixed in:6.8.0-1035.37~22.04.1USN-7703-2

Fixed in:6.8.0-1035.37USN-7703-1

linux-image-aws-64kUbuntu

Fixed in:6.8.0-1035.37~22.04.1USN-7703-2

linux-image-aws-64k-6.8Ubuntu

Fixed in:6.8.0-1035.37~22.04.1USN-7703-2

Fixed in:6.8.0-1035.37USN-7703-1

linux-image-aws-64k-lts-24.04Ubuntu

Fixed in:6.8.0-1035.37USN-7703-1

linux-image-aws-lts-24.04Ubuntu

Fixed in:6.8.0-1035.37USN-7703-1

linux-image-azureUbuntu

Fixed in:6.8.0-1034.39~22.04.1USN-7737-1

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-azure-6.8Ubuntu

Fixed in:6.8.0-1034.39~22.04.1USN-7737-1

Fixed in:6.8.0-1034.39USN-7737-1

linux-image-azure-fdeUbuntu

Fixed in:6.8.0-1034.39~22.04.1USN-7737-1

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-azure-fde-6.8Ubuntu

Fixed in:6.8.0-1034.39~22.04.1USN-7737-1

Fixed in:6.8.0-1034.39USN-7737-1

linux-image-azure-fde-lts-24.04Ubuntu

Fixed in:6.8.0-1034.39USN-7737-1

linux-image-azure-lts-24.04Ubuntu

Fixed in:6.8.0-1034.39USN-7737-1

linux-image-azure-nvidiaUbuntu

Fixed in:6.8.0-1022.23USN-7737-1

linux-image-azure-nvidia-6.8Ubuntu

Fixed in:6.8.0-1022.23USN-7737-1

linux-image-azure-nvidia-lts-24.04Ubuntu

Fixed in:6.8.0-1022.23USN-7737-1

linux-image-gcpUbuntu

Fixed in:6.8.0-1036.38~22.04.1USN-7703-2

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-gcp-6.8Ubuntu

Fixed in:6.8.0-1036.38~22.04.1USN-7703-2

Fixed in:6.8.0-1036.38USN-7703-2

linux-image-gcp-64kUbuntu

Fixed in:6.8.0-1036.38~22.04.1USN-7703-2

Fixed in:6.11.0-1015.15~24.04.1USN-7521-1

linux-image-gcp-64k-6.8Ubuntu

Fixed in:6.8.0-1036.38~22.04.1USN-7703-2

Fixed in:6.8.0-1036.38USN-7703-2

linux-image-gcp-64k-lts-24.04Ubuntu

Fixed in:6.8.0-1036.38USN-7703-2

linux-image-gcp-lts-24.04Ubuntu

Fixed in:6.8.0-1036.38USN-7703-2

linux-image-genericUbuntu

Fixed in:6.8.0-78.78USN-7703-1

linux-image-generic-6.8Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

Fixed in:6.8.0-78.78USN-7703-1

linux-image-generic-64kUbuntu

Fixed in:6.8.0-78.78USN-7703-1

linux-image-generic-64k-6.8Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

Fixed in:6.8.0-78.78USN-7703-1

linux-image-generic-64k-hwe-22.04Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-generic-64k-hwe-24.04Ubuntu

Fixed in:6.11.0-26.26~24.04.1USN-7521-1

linux-image-generic-hwe-22.04Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-generic-hwe-24.04Ubuntu

Fixed in:6.11.0-26.26~24.04.1USN-7521-1

linux-image-generic-lpaeUbuntu

Fixed in:6.8.0-78.78USN-7703-1

linux-image-gkeUbuntu

Fixed in:6.8.0-1032.36USN-7703-4

linux-image-gke-6.8Ubuntu

Fixed in:6.8.0-1032.36USN-7703-4

linux-image-gkeopUbuntu

Fixed in:6.8.0-1019.21USN-7703-2

linux-image-gkeop-6.8Ubuntu

Fixed in:6.8.0-1019.21USN-7703-2

linux-image-ibmUbuntu

Fixed in:6.8.0-1033.33USN-7703-2

linux-image-ibm-6.8Ubuntu

Fixed in:6.8.0-1033.33~22.04.1USN-7703-2

Fixed in:6.8.0-1033.33USN-7703-2

linux-image-ibm-classicUbuntu

Fixed in:6.8.0-1033.33USN-7703-2

linux-image-ibm-lts-24.04Ubuntu

Fixed in:6.8.0-1033.33USN-7703-2

linux-image-kvmUbuntu

Fixed in:6.8.0-78.78USN-7703-1

linux-image-lowlatencyUbuntu

Fixed in:6.8.0-78.78.1USN-7703-1

linux-image-lowlatency-6.8Ubuntu

Fixed in:6.8.0-78.78.1~22.04.1USN-7703-1

Fixed in:6.8.0-78.78.1USN-7703-1

linux-image-lowlatency-64kUbuntu

Fixed in:6.8.0-78.78.1USN-7703-1

linux-image-lowlatency-64k-6.8Ubuntu

Fixed in:6.8.0-78.78.1~22.04.1USN-7703-1

Fixed in:6.8.0-78.78.1USN-7703-1

linux-image-lowlatency-64k-hwe-22.04Ubuntu

Fixed in:6.8.0-78.78.1~22.04.1USN-7703-1

linux-image-lowlatency-64k-hwe-24.04Ubuntu

Fixed in:6.11.0-1014.15~24.04.1USN-7521-3

linux-image-lowlatency-hwe-22.04Ubuntu

Fixed in:6.8.0-78.78.1~22.04.1USN-7703-1

linux-image-lowlatency-hwe-24.04Ubuntu

Fixed in:6.11.0-1014.15~24.04.1USN-7521-3

linux-image-nvidiaUbuntu

Fixed in:6.8.0-1035.38USN-7703-4

linux-image-nvidia-6.8Ubuntu

Fixed in:6.8.0-1035.38~22.04.1USN-7703-4

Fixed in:6.8.0-1035.38USN-7703-4

linux-image-nvidia-64kUbuntu

Fixed in:6.8.0-1035.38USN-7703-4

linux-image-nvidia-64k-6.8Ubuntu

Fixed in:6.8.0-1035.38~22.04.1USN-7703-4

Fixed in:6.8.0-1035.38USN-7703-4

linux-image-nvidia-64k-hwe-22.04Ubuntu

Fixed in:6.8.0-1035.38~22.04.1USN-7703-4

linux-image-nvidia-hwe-22.04Ubuntu

Fixed in:6.8.0-1035.38~22.04.1USN-7703-4

linux-image-nvidia-lowlatencyUbuntu

Fixed in:6.8.0-1035.38.1USN-7703-4

linux-image-nvidia-lowlatency-6.8Ubuntu

Fixed in:6.8.0-1035.38.1USN-7703-4

linux-image-nvidia-lowlatency-64kUbuntu

Fixed in:6.8.0-1035.38.1USN-7703-4

linux-image-nvidia-lowlatency-64k-6.8Ubuntu

Fixed in:6.8.0-1035.38.1USN-7703-4

linux-image-oem-22.04Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-oem-22.04aUbuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-oem-22.04bUbuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-oem-22.04cUbuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-oem-22.04dUbuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-oem-24.04bUbuntu

Fixed in:6.11.0-1022.22USN-7521-1

linux-image-oracleUbuntu

Fixed in:6.8.0-1032.33~22.04.1USN-7703-3

linux-image-oracle-6.8Ubuntu

Fixed in:6.8.0-1032.33~22.04.1USN-7703-3

Fixed in:6.8.0-1032.33USN-7703-3

linux-image-oracle-64kUbuntu

Fixed in:6.8.0-1032.33~22.04.1USN-7703-3

linux-image-oracle-64k-6.8Ubuntu

Fixed in:6.8.0-1032.33~22.04.1USN-7703-3

Fixed in:6.8.0-1032.33USN-7703-3

linux-image-oracle-64k-lts-24.04Ubuntu

Fixed in:6.8.0-1032.33USN-7703-3

linux-image-oracle-lts-24.04Ubuntu

Fixed in:6.8.0-1032.33USN-7703-3

linux-image-raspiUbuntu

Fixed in:6.8.0-1035.39USN-7703-4

linux-image-raspi-6.8Ubuntu

Fixed in:6.8.0-1035.39USN-7703-4

linux-image-raspi-realtimeUbuntu

Fixed in:6.8.0-2028.29USN-7719-1

linux-image-raspi-realtime-6.8Ubuntu

Fixed in:6.8.0-2028.29USN-7719-1

linux-image-realtimeUbuntu

Fixed in:6.8.1-1030.31USN-7703-1

linux-image-realtime-6.8.1Ubuntu

Fixed in:6.8.1-1030.31USN-7703-1

linux-image-virtualUbuntu

Fixed in:6.8.0-78.78USN-7703-1

linux-image-virtual-6.8Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

Fixed in:6.8.0-78.78USN-7703-1

linux-image-virtual-hwe-22.04Ubuntu

Fixed in:6.8.0-78.78~22.04.1USN-7703-4

linux-image-virtual-hwe-24.04Ubuntu

Fixed in:6.11.0-26.26~24.04.1USN-7521-1

linux-lowlatencyUbuntu

Fixed in:6.8.0-78.78.1USN-7703-1

linux-lowlatency-hwe-6.11Ubuntu

Fixed in:6.11.0-1014.15~24.04.1USN-7521-3

linux-lowlatency-hwe-6.8Ubuntu

Fixed in:6.8.0-78.78.1~22.04.1USN-7703-1

linux-nvidiaUbuntu

Fixed in:6.8.0-1035.38USN-7703-4

linux-nvidia-6.8Ubuntu

Fixed in:6.8.0-1035.38~22.04.1USN-7703-4

linux-nvidia-lowlatencyUbuntu

Fixed in:6.8.0-1035.38.1USN-7703-4

linux-oem-6.11Ubuntu

Fixed in:6.11.0-1022.22USN-7521-1

linux-oracleUbuntu

Fixed in:6.8.0-1032.33USN-7703-3

linux-oracle-6.8Ubuntu

Fixed in:6.8.0-1032.33~22.04.1USN-7703-3

linux-raspiUbuntu

Fixed in:6.8.0-1035.39USN-7703-4

linux-raspi-realtimeUbuntu

Fixed in:6.8.0-2028.29USN-7719-1

linux-realtimeUbuntu

Fixed in:6.8.1-1030.31USN-7703-1

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorLocal

Attack ComplexityLow

Privileges RequiredLow

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

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

Exploit Intelligence

0.19%probability of exploitation in 30 days

9thpercentile

Low risk: more likely to be exploited than 9% of all known CVEs.

References

Patch3

Related Vulnerabilities

Other CWE-401 (Missing Release of Memory (Memory Leak)) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2020-13934	High	7.5	64%	-	Fix
CVE-2016-6304	High	7.5	63%	-	Fix
CVE-2019-12265	Medium	5.3	55%	-	Fix
CVE-2001-0136	Medium	5.0	45%	-	-
CVE-2016-4232	High	7.5	36%	-	-
CVE-2001-0543	Medium	5.0	21%	-	-

Embed a live status badge for CVE-2025-21768

Markdown

[![CVE-2025-21768](https://tridentstack.com/cve/badge/CVE-2025-21768.svg)](https://tridentstack.com/cve/CVE-2025-21768)

HTML

<a href="https://tridentstack.com/cve/CVE-2025-21768"><img src="https://tridentstack.com/cve/badge/CVE-2025-21768.svg" alt="CVE-2025-21768"></a>

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-10-28.