Critical severity · published Aug 26, 2026
CVE-2026-74744
ipvlan: inherit needed_headroom and needed_tailroom from phy_dev
9.8
CVSS
0.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 43% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
2ad7bf3638411cb547f2823df08166c13ab04269 before af602c4d0ee548da18e2409b4b4da1079625a372; 2ad7bf3638411cb547f2823df08166c13ab04269 before f3c17ff65f54781cde696e16a6c577615ed735aa; 2ad7bf3638411cb547f2823df08166c13ab04269 before c0fbe31f6b20ade0465130685859faa5c86fda59; 2ad7bf3638411cb547f2823df08166c13ab04269 before 5f33188457bbcc1b11ca87084037963c516ed3d9; 2ad7bf3638411cb547f2823df08166c13ab04269 before 5c2ca77212eb38559b0353b8363b7a84f4b019dd; 2ad7bf3638411cb547f2823df08166c13ab04269 before e16e960d55a40d36bd7c2494cc005e757dc9a1ef; +1 more · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-74744
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-74744
git.kernel.org
https://git.kernel.org/stable/c/5c2ca77212eb38559b0353b8363b7a84f4b019dd
git.kernel.org
https://git.kernel.org/stable/c/5f33188457bbcc1b11ca87084037963c516ed3d9
git.kernel.org
https://git.kernel.org/stable/c/af602c4d0ee548da18e2409b4b4da1079625a372
git.kernel.org
https://git.kernel.org/stable/c/c0fbe31f6b20ade0465130685859faa5c86fda59
git.kernel.org
https://git.kernel.org/stable/c/e16e960d55a40d36bd7c2494cc005e757dc9a1ef
git.kernel.org
https://git.kernel.org/stable/c/f3c17ff65f54781cde696e16a6c577615ed735aa
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