Vulnerability · Published Jul 8, 2026 · Assigned by VulnCheck

CVE-2026-29009U-Boot < 2026.07-rc2 Buffer Overflow in nfs_readlink_reply() via NFS READLINK

High 8.2

In plain English

A high-severity buffer overflow in u-boot from u-boot. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities).

Severity (CVSS 3.1)8.2High

Exploit odds (30 days)0.7%top 45.2% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	u-boot	no fix listed	DEBIAN-CVE-2026-29009
Debian:13	u-boot	no fix listed	DEBIAN-CVE-2026-29009
Debian:14	u-boot	no fix listed	DEBIAN-CVE-2026-29009
Ubuntu:22.04:LTS	u-boot	no fix listed	UBUNTU-CVE-2026-29009
Ubuntu:24.04:LTS	u-boot	no fix listed	UBUNTU-CVE-2026-29009
Ubuntu:25.10	u-boot	no fix listed	UBUNTU-CVE-2026-29009
Ubuntu:26.04:LTS	u-boot	no fix listed	UBUNTU-CVE-2026-29009
Ubuntu:26.10	u-boot	no fix listed	UBUNTU-CVE-2026-29009
Ubuntu:22.04:LTS	u-boot-nezha	no fix listed	UBUNTU-CVE-2026-29009
Ubuntu:24.04:LTS	u-boot-nezha	no fix listed	UBUNTU-CVE-2026-29009

Affected products (as reported)

Vendor	Product	Versions
u-boot	u-boot	0 – before 2026.07-rc2

Weakness: CWE-120 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

References

Researcher Blog technical-description, exploit
Mailing List Outreach issue-tracking
Release Notes release-notes
Patch Commit patch
Project Webpage
https://www.vulncheck.com/advisories/u-boot-rc3-buffer-overflow-in-nfs-readlink-reply-via-nfs-readlink third-party-advisory