CVE-2026-29009 u-boot CVE debrief

Who should care

Organizations using U-Boot firmware with NFS support, especially in environments where NFS servers may be compromised or malicious, should prioritize patching this vulnerability. This includes embedded systems, network devices, and other firmware-based products that utilize U-Boot and NFS functionality.

Technical summary

The vulnerability exists in the nfs_readlink_reply() function of U-Boot, which is responsible for handling NFS READLINK responses. When CONFIG_CMD_NFS is enabled, an attacker can send multiple READLINK responses with relative symlink targets of approximately 1100 bytes each. This can overflow the 2048-byte nfs_path_buff buffer, potentially corrupting adjacent BSS variables such as nfs_server_ip, nfs_server_mount_port, nfs_server_port, nfs_our_port, nfs_state, and rpc_id. Successful exploitation could lead to memory corruption and control over the NFS client state machine.

Defensive priority

High priority should be given to patching this vulnerability due to its high CVSS score of 8.8 and the potential for memory corruption and control over the NFS client state machine.

Recommended defensive actions

• Apply the official patch or update to a version of U-Boot that addresses this vulnerability.
• Disable CONFIG_CMD_NFS if not required.
• Implement compensating controls such as validating NFS server responses and monitoring for suspicious activity.
• Conduct thorough inventory checks to identify affected systems.
• Monitor for potential exploitation attempts.

Evidence notes

The CVE record was published on 2026-07-08T17:17:21.173Z and was last modified on 2026-07-10T18:01:31.563Z. The NVD entry is currently Awaiting Analysis. The vulnerability was disclosed via multiple sources including the U-Boot mailing list and VulnCheck.

Official resources