Use-after-free in Linux kernel - CVE-2026-46036

Vulnerability identifier: #VU132459

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-46036

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a use-after-free in vfio_cdx_set_msi_trigger() and the cdx_irqs array when handling concurrent VFIO_DEVICE_SET_IRQS ioctls. A local user can issue concurrent ioctl calls to trigger a use-after-free and cause a denial of service.

The issue occurs because one caller can observe config_msi as set while another caller clears it and frees the associated IRQ array.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-realtime (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (Ubuntu package)
linux-raspi (Ubuntu package)
linux-azure (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure-fde (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-27.27
linux-realtime (Ubuntu package) - update to 7.0.0-27.27.1
linux-gcp (Ubuntu package) - update to 7.0.0-1007.7
linux-oracle (Ubuntu package) - update to 7.0.0-1007.7
linux-aws (Ubuntu package) - update to 7.0.0-1008.8
linux-raspi (Ubuntu package) - update to 7.0.0-1014.14
linux-azure (Ubuntu package) - update to 7.0.0-1010.10
linux-nvidia (Ubuntu package) - update to 7.0.0-1013.13
linux-ibm (Ubuntu package) - update to 7.0.0-1009.9
linux-azure-fde (Ubuntu package) - update to 7.0.0-1009.9

• https://git.kernel.org/stable/c/670e8864b1a218d72f08db40d0103adf38fa1d9b
• https://git.kernel.org/stable/c/7530f34ec0ca1438d45a75dcb43183a1cc92eced
• https://git.kernel.org/stable/c/7b436ade16cc81095d79b79f8efa3af0a4f5c5a2
• https://git.kernel.org/stable/c/ddf96e23c366c566283fce8377928851fa7f5e81

• Use-after-free in Linux kernel vfio cdx driver
• Ubuntu update for linux
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-azure