Improper initialization in Linux kernel - CVE-2026-98641

Vulnerability identifier: #VU156953

CSH Severity: Low

CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98641

CWE-ID: CWE-665

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 kernel stack corruption and a kernel panic.

The vulnerability exists due to improper initialization of the exception callback frame pointer in the Linux kernel arm64 BPF JIT compiler when handling an exception thrown from a subprogram that uses its own BPF stack. A local privileged user can run a crafted BPF program whose exception callback passes a local variable's address to a helper, causing the helper to use a stale frame pointer and overwrite its own return address to cause 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/b67b4c763f211e7a6391c356fef552e2ea63f08a
• https://git.kernel.org/stable/c/d7cd5ebe13989f265015910faa25e5d50faa4c22
• https://git.kernel.org/stable/c/ecdd770a9fc3eaf6c3127c5991312b84774a7b0f
• https://git.kernel.org/stable/c/ef1fb82f12186dd26153b14d9fbcf4ec98db81b3

• Improper initialization in Linux kernel arm64 net
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more