PT-2026-8217 · Linux+3 · Linux Kernel+3
Valis
·
Published
2026-01-01
·
Updated
2026-05-22
·
CVE-2026-23209
CVSS v3.1
7.8
High
| Vector | AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions
Linux kernel (affected versions not specified)
Description
The Linux kernel contains a flaw within the macvlan component, specifically in the
macvlan common newlink() function. A use-after-free condition can occur when creating a new macvlan link with MACVLAN MODE SOURCE mode and MACVLAN MACADDR ADD or MACVLAN MACADDR SET parameters, if the lower device already has a macvlan port and register netdevice() fails. This failure leads to a call to free netdev(), which frees the struct net device while it is still referenced in a source entry attached to the lower device's macvlan port. Subsequently, packets sent on the macvlan port with a matching source MAC address can trigger the use-after-free in macvlan forward source(). The issue was identified through a reproduction scenario involving the creation of veth pairs and macvlan interfaces, and a detailed analysis provided by valis.Recommendations
At the moment, there is no information about a newer version that contains a fix for this vulnerability.
Exploit
Use After Free
Found an issue in the description? Have something to add? Feel free to write us 👾
Weakness Enumeration
Related Identifiers
Affected Products
Linuxmint
Linux Kernel
Rocky Linux
Ubuntu