Use-after-free in Linux kernel - CVE-2026-98616

Vulnerability identifier: #VU156924

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-2026-98616

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to cause a denial of service by triggering a kernel crash.

The vulnerability exists due to use-after-free in the Linux kernel fbnic Ethernet driver when closing a network device after failed PCIe error recovery or a failed datapath reopen during resume. A local privileged user can trigger the affected teardown sequence to cause fbnic_dbg_down() to dereference freed NAPI vectors because num_napi retains a nonzero count, resulting in 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/4bcc4a92c603fe7f062cea22e20da2e0ad6b12c3
• https://git.kernel.org/stable/c/4f4b767ffea7653a00904383908536e754f8ef5b
• https://git.kernel.org/stable/c/c5b5aee41b9f5ed0743344be1c7b544555fa3cb9

• 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