Off-by-one in Linux kernel - CVE-2026-89751
Published: September 12, 2026
Vulnerability identifier: #VU149042
CSH Severity: Low
CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-89751
CWE-ID: CWE-193
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause incorrect port I/O handling.
The vulnerability exists due to an off-by-one error in handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c when emulating port I/O operations. A local user can perform port I/O operations that invoke the affected handlers to cause incorrect port I/O handling.
Affected software
Linux kernel
How to mitigate CVE-2026-89751
Install security update from vendor's repository.
Linux kernel - update to 7.0 rc3