What is CVE-2026-80978?

CVE-2026-80978 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 3.11 onward and patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-80978 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-80978?

CVE-2026-80978 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-2026-80978?

Yes, CVE-2026-80978 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 3.11 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-80978 actively exploited?

CVE-2026-80978 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-80978

High

In the Linux kernel, the following vulnerability has been resolved: net: cap advertised IP tunnel headroom IP tunnel devices derive their advertised needed_headroom from lower output devices. A stack of user-created devices can make the derived value larger than the 16-bit skb header offsets can represent. Once IP output reserves it, skb head expansion can wrap those offsets. The runtime transmit path already caps a growing needed_headroom at 512. Apply the same cap when tunnel configuration publishes needed_headroom derived from a lower output device. Capping the advertised value is safe: IP tunnel transmit still expands the skb when a packet needs more headroom. A nonsensical stacked configuration can therefore incur an extra reallocation, but it cannot publish an unbounded reservation to upper layers.

Package Linux Kernel

Published 2026-09-11

Last modified 2026-09-14

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 3.11 and later are affected. Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, 6.18.50, 7.2.4, 7.3-rc1 and their respective stable series.

Affected from

≥ 3.11

Fixed in

✓ 5.10.270 5.10.x ✓ 5.15.221 5.15.x ✓ 6.1.188 6.1.x ✓ 6.6.157 6.6.x ✓ 6.12.109 6.12.x ✓ 6.18.50 6.18.x ✓ 7.2.4 7.2.x ✓ 7.3-rc1

References

8 total

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-80978

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-09-11

Modified 2026-09-14

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-80978?

CVE-2026-80978 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 3.11 onward and has been patched in 5.10.270, 5.15.221, 6.1.188 and others. CVE-2026-80978 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-80978?

CVE-2026-80978 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-2026-80978?

Yes. CVE-2026-80978 has been patched. Fixed versions include 5.10.270, 5.15.221, 6.1.188 and others. If you are running Linux kernel 3.11 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-80978 actively exploited?

No. CVE-2026-80978 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.