CVE-2026-53203: Linux Kernel Intel VPU Buffer Overflow – CVSS 7.1 HIGH

Technical summary

CVE-2026-53203 is a buffer overflow vulnerability in the accel/ivpu subsystem of the Linux kernel. The vulnerability occurs in the MS get_info_ioctl function, which handles metric stream information queries from firmware. The flaw stems from insufficient validation of the info size returned by firmware against the allocated buffer size. If firmware returns a size larger than the buffer, the driver proceeds with an incorrect buffer copy instead of rejecting the operation. The patch adds explicit overflow checking and returns -EOVERFLOW when the firmware-reported size exceeds the buffer capacity. The vulnerability is classified as CWE-120 (Buffer Copy without Checking Size of Input) and CWE-787 (Out-of-bounds Write).

Business impact

Organizations deploying systems with Intel VPU acceleration hardware and vulnerable Linux kernels face elevated risk of local privilege escalation and information disclosure. A local attacker could exploit this vulnerability to read sensitive kernel memory or trigger denial of service conditions. The impact is particularly significant for edge computing, AI inference, and specialized computing environments that rely on VPU acceleration. While the attack requires local access, the combination of information disclosure and availability impact makes this a material operational risk for affected deployments.

Affected systems

The Linux kernel versions prior to the patch are affected. This specifically impacts systems with Intel VPU (accel/ivpu) hardware and drivers enabled. Vulnerable systems include those running affected kernel versions on Intel Arc GPUs or other Intel VPU-equipped hardware. The vulnerability does not affect systems without VPU acceleration hardware or those running patched kernel versions. Verify the specific kernel version and VPU driver status in your environment against vendor advisories.

Exploitability

Exploitation requires local access (CWE vector shows AV:L—local attack vector). An authenticated local user can trigger the vulnerable ioctl without special privileges (PR:L—low privilege required). The attack is straightforward to execute once local access is obtained, with no user interaction required (UI:N). However, the barrier to entry is meaningful: the attacker must have local shell access or be an unprivileged local process. The vulnerability is not wormable or remotely exploitable in isolation.

Remediation

Apply the Linux kernel security patch that adds buffer overflow validation to the accel/ivpu MS get_info_ioctl function. The patch implements explicit size checking and returns -EOVERFLOW when firmware reports a size exceeding the allocated buffer. After patching, reboot affected systems to load the corrected kernel. For systems that cannot be immediately patched, consider disabling VPU acceleration or restricting local access where operationally feasible. Verify patch application by confirming kernel version matches or exceeds the fixed version provided in your distribution's advisory.

Patch guidance

Identify systems running Linux with Intel VPU acceleration enabled by checking dmesg for ivpu driver initialization or verifying hardware presence. Obtain the appropriate patched kernel version from your Linux distribution (check vendor security advisories for Red Hat, Ubuntu, Debian, SUSE, etc.). Test the patched kernel in a non-production environment to ensure compatibility with dependent workloads. Schedule reboots during maintenance windows to deploy the kernel update. After reboot, verify the kernel version has been updated and that VPU functionality remains operational. Prioritize systems with exposed VPU drivers and multi-tenant workloads.

Detection guidance

Monitor system logs for metric stream query operations and any -EOVERFLOW returns from ivpu ioctl calls, though this signal is weak post-exploitation. Check kernel version via 'uname -r' and cross-reference against vendor patch advisories to identify unpatched systems. Use endpoint detection and response (EDR) tools to monitor for suspicious ioctl activity targeting /dev/accel* or ivpu device files. Audit local user accounts and SSH access logs to identify potential lateral movement that could precede VPU-targeted exploitation. Firmware telemetry from VPU hardware (if available) may log oversized metric stream responses.

Why prioritize this

This vulnerability merits prompt attention due to its HIGH CVSS score (7.1), combination of confidentiality and availability impacts, and the reality that local access is often achievable in multi-tenant or compromised systems. However, the local-only attack vector means it is lower priority than remote code execution vulnerabilities. Organizations should address this in the same patching cycle as other local privilege escalation flaws affecting their VPU-accelerated infrastructure. Prioritize systems with untrusted user access, containerized workloads sharing VPU hardware, or edge devices with multiple administrative users.

Risk score, explained

CVSS 7.1 (HIGH) reflects: (1) local attack vector limiting initial access requirements; (2) low privilege required, making exploitation possible by ordinary users; (3) high confidentiality impact through kernel memory disclosure; (4) high availability impact via denial of service; (5) no scope change, impact contained to the affected system. The score does not assume pre-existing local compromise, but rather that a legitimate local user exploits the driver flaw. The moderate score relative to remote code execution flaws is appropriate given the local-only nature, but the combination of C+A impacts and ease of triggering justifies HIGH severity classification.

Frequently asked questions