NULL pointer dereference in Linux kernel - CVE-2026-98038
Published: September 28, 2026
Vulnerability identifier: #VU152438
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-98038
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to trigger a null pointer dereference.
The vulnerability exists due to improper reference ownership tracking in the BPF verifier when verifying BPF programs that acquire references from borrowed RCU kptrs. A local user can load a crafted BPF program that uses a borrowed RCU kptr without a required NULL check to trigger a null pointer dereference.
The issue occurs when the refcounted object does not contain a graph node and its last real reference is dropped during an RCU critical section.
Affected software
Linux kernel
How to mitigate CVE-2026-98038
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3