Netboot crash via unchecked DHCPv6 DUID lengths
Published Sep 29, 2026 · Updated Sep 29, 2026
Out-of-bounds memory access in U-Boot before 2026.10-rc5 allows remote attackers to crash netboot via crafted DHCPv6 responses. In dhcp6_parse_options(), an unchecked SERVERID length reaches a copy into the fixed transmit buffer, while an unchecked CLIENTID length makes memcmp read past the stored DUID. Exploitation requires an attacker on the local link to answer a DHCPv6 SOLICIT while the device is netbooting; the documented consequences are an out-of-bounds write and read.
Summary
What happened
Out-of-bounds memory access in U-Boot before 2026.10-rc5 allows remote attackers to crash netboot via crafted DHCPv6 responses. In dhcp6_parse_options(), an unchecked SERVERID length reaches a copy into the fixed transmit buffer, while an unchecked CLIENTID length makes memcmp read past the stored DUID. Exploitation requires an attacker on the local link to answer a DHCPv6 SOLICIT while the device is netbooting; the documented consequences are an out-of-bounds write and read.
The record
- CVE
- CVE-2026-74225
- Published
- Sep 29, 2026
- Updated
- Sep 29, 2026
- Vendor
- DENX Software Engineering GmbH
- Product
- U-Boot
- Classifications
- T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 29, 2026CVE publishedPublication date reported by the CVE source.
- Sep 29, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2026.10-rc5
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Activity data is delayed. The latest report is Sep 28, 2026.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Get started to see how Hinoki identifies affected software and validates exploitability in your environment.
Get started