CVE-2026-74225

Received Received - Intake

Out-of-Bounds Memory Access in U-Boot Bootloader

Publication date: 2026-09-29

Last updated on: 2026-09-29

Assigner: VulnCheck

Description

U-Boot before 2026.10-rc5 contains out-of-bounds memory access in dhcp6_parse_options() that fails to validate SERVERID and CLIENTID option lengths from DHCPv6 packets. Attackers on the local network can send crafted DHCPv6 ADVERTISE or REPLY packets during netboot to corrupt memory and crash the bootloader.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published

2026-09-29

Last Modified

2026-09-29

Generated

2026-09-30

AI Q&A

2026-09-30

EPSS Evaluated

N/A

NVD

CVE-2026-74225

Affected Vendors & Products

Vendor	Product	Version / Range
denx	uboot	to 2026.10-rc5 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

U-Boot before version 2026.10-rc5 has a flaw in the dhcp6_parse_options() function where it does not properly check the lengths of SERVERID and CLIENTID options in DHCPv6 packets. This allows out-of-bounds memory access, which attackers can exploit by sending specially crafted DHCPv6 ADVERTISE or REPLY packets during netboot. The result is memory corruption and a crash of the bootloader.

Detection Guidance

This vulnerability involves out-of-bounds memory access in U-Boot's DHCPv6 handling. Detection requires monitoring network traffic for malformed DHCPv6 packets with oversized SERVERID or CLIENTID options. Use packet capture tools like tcpdump or Wireshark to inspect DHCPv6 traffic for non-standard option lengths.

Impact Analysis

If you use U-Boot for netboot on a local network, an attacker on the same network could send malicious DHCPv6 packets to crash the bootloader. This could prevent your system from booting properly, leading to denial of service or potential unauthorized access if combined with other exploits.

Mitigation Strategies

Upgrade U-Boot to version 2026.10-rc5 or later to address the out-of-bounds memory access issue. If upgrading is not immediately possible, restrict network access to DHCPv6 services during netboot or disable netboot functionality until the patch is applied.

Hi! I’m here to help you understand CVE-2026-74225. Ask me anything about the vulnerability, its impact, or mitigation strategies.

0/70