CVE intelligence

CVE-2026-74744

Vulnerability intelligence

Published Aug 26, 2026Sources checked Oct 28, 2026

9.8CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-74744 and is rated Critical severity with a CVSS score of 9.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Oct 2, 2026

Release Notes

Vendor-listed releases

6.6.157.1-1

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-74744?

In the Linux kernel, the following vulnerability has been resolved:

ipvlan: inherit needed_headroom and needed_tailroom from phy_dev

ipvlan devices inherit hard_header_len from phy_dev during ipvlan_init(), but leave needed_headroom and needed_tailroom set to 0.

When the underlying phy_dev (or stacked lower device) 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() / ipvlan_hard_header() prepends header data or when lower devices append tailroom.

Fix this by: 1. Inheriting needed_headroom and needed_tailroom from phy_dev in ipvlan_init().

2. Propagating needed_headroom and needed_tailroom updates to attached ipvlans in ipvlan_device_event() when receiving NETDEV_FEAT_CHANGE events.

Source: NVD