NULL pointer dereference in Linux kernel - CVE-2026-89439
Published: September 12, 2026
Vulnerability identifier: #VU149366
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89439
CWE-ID: CWE-476
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a null pointer dereference in the isst_if_get_tpmi_instance_count function in the ISST TPMI core when handling a TPMI instance-count request for a socket whose instance failed to load. A local user can request an instance count for a socket whose instance failed to load to cause a denial of service.
Affected software
Linux kernel
How to mitigate CVE-2026-89439
Install security update from vendor's repository.