Out-of-bounds write in Linux kernel - CVE-2026-72399
Published: August 15, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to an out-of-bounds write in enetc_xdp_xmit when processing xdp_frame structures with too many fragments. A local user can provide a crafted xdp_frame with more fragments than ENETC_MAX_SKB_FRAGS to cause a denial of service.
The issue occurs because the xdp_redirect_arr array is sized to ENETC_MAX_SKB_FRAGS while an xdp_frame may contain a greater number of fragments.
Affected software
Ubuntu
linux (Ubuntu package)
linux-gcp (Ubuntu package)
How to mitigate CVE-2026-72399
linux (Ubuntu package) - addressed in versions 7.0.0-34.34, 7.0.0-34.34.1, 7.0.0-34.34~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14, 7.0.0-1020.20
linux-gcp (Ubuntu package) - addressed in versions 7.0.0-1013.13, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14
External References
- https://git.kernel.org/stable/c/1681cc7974a6123f5d5740b03bc11e4784bd2542
- https://git.kernel.org/stable/c/1ecb199b0e6d12ab6c26c0b7edf1a8f4472d9aed
- https://git.kernel.org/stable/c/555c5475e787802eeae0d2b91c2f66c330db2767
- https://git.kernel.org/stable/c/cfbc6e9b84dcc0aa2d65c84ea4745af327763209
- https://git.kernel.org/stable/c/d22829101ab675607ad6c3d420fb3ab875f46bbb
- https://git.kernel.org/stable/c/f55276160ffad3e235b657ee4b7304eb99b90e5c