CVE-2026-53044

What it actually does

This flaw is an out-of-bounds access bug in the Linux kernel Tegra CBB SoC driver. An incorrect ARRAY_SIZE() calculation in fabric lookup tables can cause the kernel to read past the intended table boundary while processing a target timeout lookup. In practical terms, the most likely technical outcome is kernel instability, including an oops, panic, or denial of service on affected NVIDIA Tegra-based systems. Because the issue occurs in kernel code, impact depends on platform configuration and whether an attacker or faulty device behavior can trigger the affected timeout-handling path. There is no public exploit maturity reported, the EPSS score is very low, and it is not listed in CISA KEV.

Why it matters to the business

Organizations running Linux on affected Tegra-based hardware could experience unexpected system crashes or degraded reliability if the vulnerable code path is triggered. This is most relevant for embedded, edge, automotive, robotics, appliance, and IoT deployments where Tegra platforms are common and downtime may require physical intervention. Current exploitation likelihood appears low, with no KEV listing and no known mature exploit, but kernel memory-corruption fixes should still be prioritized through normal platform maintenance because operational outages on embedded devices can be costly.

How an attack unfolds

An attacker would first need access to a system or interface capable of influencing Tegra CBB fabric behavior or triggering a target timeout condition. By causing the kernel's Tegra CBB driver to perform a timeout lookup, the vulnerable lookup logic may use an incorrect table size and access memory beyond the intended fabric lookup table. If the out-of-bounds access hits invalid or unexpected memory, the kernel may fault, leading to an oops or panic. At present, there is no evidence of public weaponization, ransomware use, or known threat actor exploitation, and reliable exploitation beyond denial of service is not established from the available information.

How to fix it

Apply the Linux kernel update that includes the upstream fix for the Tegra CBB fabric lookup table ARRAY_SIZE issue. Because no affected product list or exact fixed package versions were provided, remediation should be performed by updating to the latest vendor-supported kernel for the relevant Tegra-based distribution, board support package, embedded firmware image, or appliance release. For products using custom or long-term-support kernels, backport the upstream patch titled 'soc/tegra: cbb: Fix incorrect ARRAY_SIZE in fabric lookup tables' and rebuild/deploy the kernel. If immediate patching is not possible, reduce exposure by limiting untrusted local access, disabling unnecessary device interfaces, monitoring for repeated Tegra CBB timeout events, and planning maintenance windows for kernel replacement on embedded devices.

How to confirm the fix worked

Confirm that the running kernel or vendor firmware includes the Tegra CBB ARRAY_SIZE fix. For source-based kernels, verify that the Tegra CBB fabric lookup code no longer derives lookup bounds from the wrong table/object and that the relevant upstream patch is present in the kernel tree. For packaged systems, compare the installed kernel version against the vendor advisory or changelog that references the Tegra CBB fabric lookup fix. After updating, reboot into the fixed kernel and verify with uname, package manager metadata, or firmware inventory tooling that the active kernel is the patched one. Operational validation should include reviewing kernel logs for absence of recurring Tegra CBB target timeout lookups followed by oops, panic, or paging faults.

Typical attack path

1. Identify a Linux system running on NVIDIA Tegra hardware with the affected Tegra CBB driver code present.
2. Gain local, device-level, or adjacent control sufficient to trigger fabric target timeout behavior, or abuse a reachable hardware/software path that can induce such timeouts.
3. Cause the Tegra CBB timeout-handling path to execute.
4. The kernel performs the vulnerable fabric lookup using the incorrect ARRAY_SIZE-derived bound.
5. The out-of-bounds access causes kernel instability, potentially resulting in an oops, panic, reboot, or service interruption.

How to detect it

There are no publicly known exploitation-specific indicators for this vulnerability. Detection should focus on evidence that the vulnerable code path was triggered and caused kernel instability. Review persistent kernel logs, system journal data, crash dumps, watchdog reset records, remote console output, and embedded device telemetry for Tegra CBB or target-timeout messages immediately followed by kernel oops, paging faults, panic, watchdog reset, or unexpected reboot. Useful sources include journalctl/kern.log, dmesg ring-buffer captures, pstore/ramoops, kdump/vmcore artifacts, bootloader reset reasons, hardware watchdog logs, and centralized syslog/SIEM events. Because similar symptoms may result from hardware faults or benign driver bugs, correlate events with unusual local activity, device I/O patterns, peripheral resets, repeated attempts over time, or activity from untrusted users/processes before treating them as suspected exploitation.

• tegra-cbb
• tegra_cbb
• CBB
• target timeout
• fabric lookup
• Unable to handle kernel paging request
• Internal error: Oops
• Oops:
• Kernel panic - not syncing
• watchdog: watchdog0: watchdog did not stop!
• pstore
• ramoops

What your security team should do

• Inventory Linux systems and embedded products running on NVIDIA Tegra-based hardware or using vendor kernels with the Tegra CBB driver enabled.
• Check vendor kernel, BSP, firmware, and appliance advisories for inclusion of the Tegra CBB ARRAY_SIZE fabric lookup fix.
• Patch or rebase affected kernels during the next appropriate maintenance window; prioritize devices where crashes could cause safety, availability, or remote-maintenance impact.
• For custom kernels, backport the upstream fix and include it in the next signed firmware or kernel release.
• Monitor kernel logs from Tegra-based systems for CBB target timeout messages followed by kernel oops, panic, or reboot events.
• Limit untrusted local access and unnecessary hardware/device interfaces on systems that cannot be patched immediately.
• Treat repeated unexplained Tegra CBB timeout crashes as suspicious until hardware faults, driver bugs, and intentional triggering are ruled out.