CVE-2026-63962 Linux CVE debrief

Who should care

Linux kernel maintainers, Linux distribution vendors, and users of Linux-based systems should be aware of this vulnerability. The vulnerability could potentially allow an attacker to crash the system or execute arbitrary code. Linux kernel configurations should be reviewed and updated to ensure USB Type-C Power Delivery is properly configured.

Technical summary

The Linux kernel was vulnerable to an out-of-bounds write in the USB Type-C Power Delivery (PD) driver, specifically in the tcpm_pd_svdm() function. This function did not properly validate the number of VDOs (Vendor-Defined Objects) in an incoming Discover Modes ACK. A malicious port partner could exploit this vulnerability to trigger an out-of-bounds write in the altmode_desc array. The vulnerability has been resolved by moving the bounds check inside the loop. This fix prevents the out-of-bounds write by ensuring that the array is not indexed past its maximum size, regardless of the number of VDOs supplied by the partner. Linux kernel maintainers, Linux distribution vendors, and users of Linux-based systems should be aware of this vulnerability and take necessary actions to mitigate the risk. The fix involves updating to a patched Linux kernel version or applying mitigations through configuration changes or monitoring system logs for potential exploitation attempts.

Defensive priority

High, as the vulnerability could allow an attacker to crash the system or execute arbitrary code, and the fix involves updating to a patched Linux kernel version or applying mitigations through configuration changes or monitoring system logs for potential exploitation attempts. System administrators and security teams should prioritize patching and verifying system configurations to mitigate the risk of exploitation. Additionally, compensating controls such as monitoring and asset inventory management should be implemented to detect and respond to potential attacks. Rollback change windows and source tracking can also be used to ensure the vulnerability is properly addressed and to track the effectiveness of mitigation efforts. Exposure review and compensating controls should be implemented for exposed systems while remediation is scheduled and verified. Monitoring and detection capabilities should be reviewed to ensure they can detect potential exploitation attempts. Asset inventory management should be used to track affected systems and prioritize patching efforts. Source tracking can be used to monitor the effectiveness of mitigation efforts and identify potential vulnerabilities in the supply chain. By prioritizing these defensive measures, organizations can reduce the risk of exploitation and minimize the impact of a potential attack. It is essential to apply the official patch or update to a fixed Linux kernel version as soon as possible to prevent exploitation. Reviewing and updating Linux kernel configurations to ensure USB Type-C Power Delivery is properly configured can also help mitigate the risk. Monitoring system logs for potential exploitation attempts can help detect and respond to potential attacks. Implementing compensating controls such as monitoring, asset inventory management, and source tracking can also help reduce the risk of exploitation. By taking these defensive measures, organizations can protect their systems from potential attacks and minimize the impact of a vulnerability. The vulnerability has been resolved by moving the bounds check inside the loop, and the fix involves updating to a patched Linux kernel version or applying mitig

Recommended defensive actions

• Apply the official patch or update to a fixed Linux kernel version
• Review and update Linux kernel configurations to ensure USB Type-C Power Delivery is properly configured
• Monitor system logs for potential exploitation attempts
• Perform exposure review for affected systems
• Implement compensating controls for exposed systems
• Use asset inventory management to track affected systems
• Use source tracking to monitor the effectiveness of mitigation efforts

Evidence notes

The vulnerability was discovered and reported by an unknown researcher. The CVE record was published on 2026-07-19T16:17:15.163Z and has not been modified since then. The NVD entry is currently Received. Further verification and review of system logs are necessary to confirm potential exploitation attempts. Linux kernel maintainers and distribution vendors should verify the official patch and update to a fixed Linux kernel version.

Official resources