CVE-2026-29009 U-Boot < 2026.07-rc2 Buffer Overflow in nfs_readlink_reply() via NFS READLINK
A malicious NFS server can trigger a buffer overflow in U-Boot's NFS client, potentially leading to memory corruption and code execution during boot.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-29009?
CVE-2026-29009 is a high-severity memory corruption vulnerability in u-boot, published on 8 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-120
Which versions are affected by CVE-2026-29009?
It affects 1 product.
Products include Denx U-Boot.
How do I fix CVE-2026-29009?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-29009 being exploited?
There is no known exploitation of CVE-2026-29009 in the wild and no public exploit code.
Other vulnerabilities in u-boot
Sources
Also known as DEBIAN-CVE-2026-29009, GHSA-rqrq-75p3-gc68, OESA-2026-2994, UBUNTU-CVE-2026-29009.