Double free in Linux kernel - CVE-2026-98473

Vulnerability identifier: #VU156773

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98473

CWE-ID: CWE-415

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to potentially cause a denial of service through a double-free during resource cleanup.

The vulnerability exists due to a potential double-free in the Linux kernel s390 vfio-ap function vfio_ap_free_aqic_resources() when cleanup runs after vfio_ap_mdev_unset_kvm() has cleared the KVM pointer. A local user can exercise repeated resource cleanup under this teardown condition to encounter a saved_isc value that was not invalidated, potentially causing a double-free and a denial of service.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/3c3433657c82f200dae36c29e2b80681c81b85be
• https://git.kernel.org/stable/c/65e05ec252a9b79e75930d3c4dd42d8877db04c5
• https://git.kernel.org/stable/c/cf441a0db681dfad5e89b015d6be11365159d7a9
• https://git.kernel.org/stable/c/da69d3ac53490724eba0ade9deb4e539a6ae9034

• Double free in Linux kernel s390 crypto driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more