What is CVE-2025-40173?

CVE-2025-40173 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 4.7 onward and patched in 5.4.301, 5.10.246, 5.15.196 and others. CVE-2025-40173 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2025-40173?

CVE-2025-40173 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2025-40173?

Yes, CVE-2025-40173 has been patched. Fixed versions include 5.4.301, 5.10.246, 5.15.196 and others. If you are running Linux kernel 4.7 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2025-40173 actively exploited?

CVE-2025-40173 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2025-40173

High

In the Linux kernel, the following vulnerability has been resolved: net/ip6_tunnel: Prevent perpetual tunnel growth Similarly to ipv4 tunnel, ipv6 version updates dev->needed_headroom, too. While ipv4 tunnel headroom adjustment growth was limited in commit 5ae1e9922bbd ("net: ip_tunnel: prevent perpetual headroom growth"), ipv6 tunnel yet increases the headroom without any ceiling. Reflect ipv4 tunnel headroom adjustment limit on ipv6 version. Credits to Francesco Ruggeri, who was originally debugging this issue and wrote local Arista-specific patch and a reproducer.

Package Linux Kernel

Published 2025-11-12

Last modified 2026-07-30

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 4.7 and later are affected. Fixed in 5.4.301, 5.10.246, 5.15.196, 6.1.158, 6.6.114, 6.12.55, 6.17.5, 6.18 and their respective stable series.

Affected from

≥ 4.7

Fixed in

✓ 5.4.301 5.4.x ✓ 5.10.246 5.10.x ✓ 5.15.196 5.15.x ✓ 6.1.158 6.1.x ✓ 6.6.114 6.6.x ✓ 6.12.55 6.12.x ✓ 6.17.5 6.17.x ✓ 6.18

References

8 total

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2025-40173

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2025-11-12

Modified 2026-07-30

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2025-40173?

CVE-2025-40173 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 4.7 onward and has been patched in 5.4.301, 5.10.246, 5.15.196 and others. CVE-2025-40173 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2025-40173?

CVE-2025-40173 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2025-40173?

Yes. CVE-2025-40173 has been patched. Fixed versions include 5.4.301, 5.10.246, 5.15.196 and others. If you are running Linux kernel 4.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2025-40173 actively exploited?

No. CVE-2025-40173 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.