CVE-2026-29009

Publication date 8 July 2026

Last updated 16 July 2026

Ubuntu priority

Cvss 3 Severity Score

Description

U-Boot through 2026.04-rc3 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.

Status

Show unmaintained releases

Package	Ubuntu Release	Status
u-boot	26.04 LTS resolute	Needs evaluation
	25.10 questing	Ignored end of life, was needs-triage
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Needs evaluation
u-boot-nezha	26.04 LTS resolute	Not in release
	25.10 questing	Not in release
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation

Severity score breakdown

CVSS version:

Base score 8.8 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Attack requirements	None
Privileges required	None
User interaction	None
Vulnerable system - Confidentiality impact	None
Vulnerable system - Integrity impact	Low
Vulnerable system - Availability impact	High
Subsequent system - Confidentiality impact	None
Subsequent system - Integrity impact	None
Subsequent system - Availability impact	None

Scores

Parameter	Value
Base score	8.8 · High
Base + Threat score	-
Base + Environmental score	-
Base + Threat + Environmental score	-

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N

Base score 8.2 · High