CVE-2026-53205 Overview
CVE-2026-53205 is a Linux kernel vulnerability in the accel/ivpu driver, which supports Intel Versatile Processing Unit (VPU) accelerator hardware. The flaw stems from missing bounds validation on read and write indices in the firmware log buffer. When firmware supplies indices greater than or equal to data_size, the driver proceeds to access memory using those invalid offsets. This results in out-of-bounds buffer access originating from kernel space. The upstream fix clamps invalid indices to safe values rather than trusting firmware-supplied data.
Critical Impact
Out-of-bounds access in the kernel ivpu driver triggered by malformed firmware log indices, which may lead to memory corruption or kernel information disclosure.
Affected Products
- Linux kernel versions containing the accel/ivpu firmware logging code prior to the fix
- Systems using Intel VPU accelerator hardware exposed through the ivpu driver
- Distributions shipping the affected kernel until backported fixes are applied
Discovery Timeline
- 2026-06-25 - CVE-2026-53205 published to NVD
- 2026-06-25 - Last updated in NVD database
Technical Details for CVE-2026-53205
Vulnerability Analysis
The accel/ivpu driver maintains a shared firmware log buffer used to consume diagnostic messages emitted by the VPU firmware. The buffer is described by a header containing read and write indices alongside a data_size field. Before the fix, the driver used those indices directly to compute offsets into the log payload without verifying that they fell within the valid range. Because the firmware populates these indices, any deviation from expected values caused the kernel to dereference memory outside the intended buffer region. This is an [CWE-125] out-of-bounds read condition rooted in unchecked input from a lower trust boundary.
Root Cause
The driver trusted firmware-supplied metadata without validation. Specifically, the read and write indices were not constrained to be less than data_size before being used to index into the log buffer payload. The patch adds explicit checks and clamps out-of-range indices to safe values.
Attack Vector
Exploitation requires that the firmware running on the VPU produce malformed or attacker-influenced log index values. An adversary capable of compromising VPU firmware, supplying a malicious firmware image, or otherwise inducing invalid indices can trigger the out-of-bounds access from kernel context. The vulnerability is not directly reachable from unprivileged userspace without first influencing firmware behavior.
The upstream fix is distributed across multiple stable branches. See the Linux kernel commit 535da9ad8420, commit 5961c7034140, commit 8ec70c0dbdf0, and commit dd1311bcf0e6 for the verified patches.
Detection Methods for CVE-2026-53205
Indicators of Compromise
- Kernel oops, panic, or KASAN reports referencing ivpu_fw_log or related symbols in the accel/ivpu driver
- Unexpected dmesg entries showing malformed firmware log activity or truncated log reads from the VPU
- Loaded VPU firmware images whose hashes do not match vendor-signed baselines
Detection Strategies
- Enable KASAN on test kernels to surface out-of-bounds reads in the ivpu log path during firmware integration testing
- Track kernel version inventory and flag hosts running ivpu-enabled kernels that predate the referenced stable commits
- Compare loaded VPU firmware blob hashes against expected vendor-provided values during boot
Monitoring Recommendations
- Forward dmesg and kern.log output to a centralized log platform and alert on ivpu driver fault traces
- Monitor file integrity for firmware files under /lib/firmware/intel/vpu/ and changes to the ivpu kernel module
- Audit users and processes that load or replace VPU firmware images
How to Mitigate CVE-2026-53205
Immediate Actions Required
- Apply the upstream Linux kernel patches referenced in the NVD entry or update to a distribution kernel that includes the bounds-check fix
- Restrict firmware loading paths so that only signed, vendor-supplied VPU firmware can be installed on production hosts
- Where the VPU accelerator is not used, blacklist the intel_vpu / ivpu kernel module to remove the attack surface
Patch Information
The fix adds validation that read and write indices are less than data_size before use and clamps out-of-bounds values. Verified patches are available in the upstream stable tree: 535da9ad8420, 5961c7034140, 8ec70c0dbdf0, and dd1311bcf0e6. Rebuild and reboot into the patched kernel to activate the fix.
Workarounds
- Unload the ivpu module on systems that do not require VPU acceleration using modprobe -r intel_vpu
- Add blacklist intel_vpu to /etc/modprobe.d/ to prevent automatic loading at boot
- Enforce kernel module signature verification and lockdown mode to prevent unauthorized firmware substitution
# Disable the ivpu driver until a patched kernel is deployed
echo 'blacklist intel_vpu' | sudo tee /etc/modprobe.d/disable-ivpu.conf
sudo modprobe -r intel_vpu
sudo update-initramfs -u
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
