What is CVE-2026-74743?

CVE-2026-74743 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10, affecting Linux kernel versions from 2.6.23 onward and patched in 6.1.184, 6.6.153, 6.12.105 and others. CVE-2026-74743 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-74743?

CVE-2026-74743 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-2026-74743?

Yes, CVE-2026-74743 has been patched. Fixed versions include 6.1.184, 6.6.153, 6.12.105 and others. If you are running Linux kernel 2.6.23 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-74743 actively exploited?

CVE-2026-74743 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-74743

Critical

In the Linux kernel, the following vulnerability has been resolved: macvlan: inherit needed_headroom and needed_tailroom from lowerdev macvlan devices inherit hard_header_len from lowerdev during macvlan_init(), but leave needed_headroom and needed_tailroom set to 0. When the underlying lowerdev requires extra headroom or tailroom for headers/trailers (e.g. macsec, ipsec, wireguard, tunnels, or veth with rx headroom), upper layers calculating packet headroom and tailroom fail to reserve sufficient space. This can result in reallocation overhead, skb headroom underflows, or KASAN slab-use-after-free crashes when dev_hard_header() / macvlan_hard_header() prepends header data or when lower devices append tailroom. Fix this by: 1. Inheriting needed_headroom and needed_tailroom from lowerdev in macvlan_init(). 2. Propagating needed_headroom and needed_tailroom updates to attached macvlans in macvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.

Package Linux Kernel

Published 2026-08-26

Last modified 2026-08-27

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 2.6.23 and later are affected. Fixed in 6.1.184, 6.6.153, 6.12.105, 6.18.46, 7.1.10, 7.2 and their respective stable series.

Affected from

≥ 2.6.23

Fixed in

✓ 6.1.184 6.1.x ✓ 6.6.153 6.6.x ✓ 6.12.105 6.12.x ✓ 6.18.46 6.18.x ✓ 7.1.10 7.1.x ✓ 7.2

References

6 total

Showing 5 of 6 references View all on NVD

Details

CVE ID CVE-2026-74743

Severity Critical

CVSS score 9.8 / 10

CVSS version 3.1

Published 2026-08-26

Modified 2026-08-27

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-74743?

CVE-2026-74743 is a Critical severity Linux kernel vulnerability with a CVSS score of 9.8 out of 10 . It affects Linux kernel versions from 2.6.23 onward and has been patched in 6.1.184, 6.6.153, 6.12.105 and others. CVE-2026-74743 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-74743?

CVE-2026-74743 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-2026-74743?

Yes. CVE-2026-74743 has been patched. Fixed versions include 6.1.184, 6.6.153, 6.12.105 and others. If you are running Linux kernel 2.6.23 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-74743 actively exploited?

No. CVE-2026-74743 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.