CVE-2026-74744: Linux kernel · ipvlan: inherit needed_headroom and needed_tailroom from phy_dev
Source GCVE Database
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
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.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74744 (opens in a new tab)
- git.kernel.org/stable/c/5c2ca77212eb38559b0353b8363b7a84f4b019dd (opens in a new tab)
- git.kernel.org/stable/c/5f33188457bbcc1b11ca87084037963c516ed3d9 (opens in a new tab)
- git.kernel.org/stable/c/af602c4d0ee548da18e2409b4b4da1079625a372 (opens in a new tab)
- git.kernel.org/stable/c/c0fbe31f6b20ade0465130685859faa5c86fda59 (opens in a new tab)
- git.kernel.org/stable/c/e16e960d55a40d36bd7c2494cc005e757dc9a1ef (opens in a new tab)
- git.kernel.org/stable/c/f3c17ff65f54781cde696e16a6c577615ed735aa (opens in a new tab)