CVE-2026-63862 Linux CVE debrief

Who should care

Linux kernel users and administrators should review and apply patches for CVE-2026-63862. They should also verify system configurations and inventory for potential exposure. Additionally, they should monitor Linux kernel updates for additional information.

Technical summary

The Linux kernel vulnerability CVE-2026-63862 is related to the PCI: mediatek-gen3 component. The vulnerability has been resolved by reversing the order of IRQ domain allocation and controller IRQ fetching in the mtk_pcie_setup_irq() function. This change prevents leaking IRQ domains when the IRQ is not found. The vulnerability was flagged by Sashiko during a review of a patch series for the Linux kernel.

Defensive priority

Medium

Recommended defensive actions

• Review and apply patches for CVE-2026-63862
• Monitor Linux kernel updates for additional information
• Verify system configurations and inventory for potential exposure
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further review of Linux kernel documentation and source code may be necessary for detailed understanding. The vulnerability was flagged by Sashiko during a review of a patch series for the Linux kernel. The patch series aimed to add power control support for the mediatek-gen3 component. The vulnerability is related to the handling of IRQ domains in the mtk_pcie_setup_irq() function. The function allocates IRQ domains before fetching the controller's IRQ, which can lead to leaking IRQ domains if the IRQ fetch fails.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.