Use-after-free in Linux kernel - CVE-2026-98642

Vulnerability identifier: #VU156954

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-2026-98642

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to potentially cause a denial of service by triggering a kernel use-after-free.

The vulnerability exists due to a use-after-free in the Linux kernel BPF memory allocator when alloc_bulk() consumes list nodes concurrently with RCU Tasks Trace cleanup. A local user can trigger concurrent BPF memory allocation and reclamation operations to potentially crash the kernel by causing access to freed list nodes.

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/1c21452d02eec2f008e2c5535820f85adbd7587a
• https://git.kernel.org/stable/c/1d6581b544a88cf4348c2fb60dcb50ad63f012da
• https://git.kernel.org/stable/c/a0e150a118025a05c8662c536ba2a865da86419c
• https://git.kernel.org/stable/c/f101602415fb39a58941bec444df65634d5a6844

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