CVE-2026-74743 Affecting kernel-macros package, versions <5.14.21-150400.24.240.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
0.7% (52nd percentile)

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  • Snyk IDSNYK-SLES154-KERNELMACROS-20059102
  • published23 Sept 2026
  • disclosed22 Sept 2026

Introduced: 22 Sep 2026

NewCVE-2026-74743  (opens in a new tab)

How to fix?

Upgrade SLES:15.4 kernel-macros to version 5.14.21-150400.24.240.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-macros package and not the kernel-macros package as distributed by SLES. See How to fix? for SLES:15.4 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1