Vulnerability Description
U-Boot before 2026.07-rc2 contains a buffer overflow vulnerability in nfs_readlink_reply() (net/nfs-common.c) when CONFIG_CMD_NFS is enabled, allowing a malicious or compromised NFS server to overflow the 2048-byte nfs_path_buff buffer by returning multiple relative symlink targets that are appended without cumulative length validation. Attackers can send two or more READLINK responses containing relative symlink targets of approximately 1100 bytes each to corrupt adjacent BSS variables including nfs_server_ip, nfs_server_mount_port, nfs_server_port, nfs_our_port, nfs_state, and rpc_id, potentially achieving memory corruption and control over the NFS client state machine.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Denx | U-Boot | < 2026.04 |
Related Weaknesses (CWE)
References
- https://git.u-boot-project.org/u-boot/u-boot/-/commit/d6694018eaddefac6aae974f9c
- https://git.u-boot-project.org/u-boot/u-boot/-/releases/v2026.07-rc2
- https://lists.denx.de/pipermail/u-boot/2026-May/617853.htmlMailing ListThird Party Advisory
- https://u-boot.org/Product
- https://www.vulncheck.com/advisories/u-boot-rc3-buffer-overflow-in-nfs-readlink-ExploitThird Party Advisory
- https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/ExploitThird Party Advisory
FAQ
What is CVE-2026-29009?
CVE-2026-29009 is a vulnerability with a CVSS score of 8.2 (HIGH). U-Boot before 2026.07-rc2 contains a buffer overflow vulnerability in nfs_readlink_reply() (net/nfs-common.c) when CONFIG_CMD_NFS is enabled, allowing a malicious or compromised NFS server to overflow...
How severe is CVE-2026-29009?
CVE-2026-29009 has been rated HIGH with a CVSS base score of 8.2/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-29009?
Check the references section above for vendor advisories and patch information. Affected products include: Denx U-Boot.