Use-after-free in Linux kernel - CVE-2026-98617

Vulnerability identifier: #VU156926

CSH Severity: Low

CVSS v4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98617

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to potentially cause a denial of service through access to freed kernel memory.

The vulnerability exists due to use-after-free in the Linux kernel fbnic driver's fbnic_queue_mem_alloc() function when restarting a receive queue after a failed PCIe recovery or resume has left the datapath torn down while netif_running() remains true. A local privileged user can trigger a queue restart in this state to access previously freed rings and NAPI vectors, potentially causing a kernel crash.

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/1fb569cf3bf97e552f465b2c719e36b48ae7c18b
• https://git.kernel.org/stable/c/b5d9e9d4d0c13bc8b60d8d97e7a07fb25fea639e

• Use-after-free in Linux kernel meta fbnic driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more