CVE-2026-34960Public exploit

Boot interruption via unbounded DHCP option scan

Published May 11, 2026 · Updated May 11, 2026

Out-of-bounds read in DHCP parsing in barebox before 2026.04.0 allows attackers to interrupt boot with a crafted reply. The dhcp_message_type() loop advances through received option TLVs until it finds a 0xff marker but never checks the pointer against the packet's actual end. Reachability requires barebox to be performing DHCP on the same broadcast domain as a rogue responder; the resulting over-read can fault and halt the boot process.

CVSS severity7.1
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in DHCP parsing in barebox before 2026.04.0 allows attackers to interrupt boot with a crafted reply. The dhcp_message_type() loop advances through received option TLVs until it finds a 0xff marker but never checks the pointer against the packet's actual end. Reachability requires barebox to be performing DHCP on the same broadcast domain as a rogue responder; the resulting over-read can fault and halt the boot process.

The record

CVE
CVE-2026-34960
Published
May 11, 2026
Updated
May 11, 2026
Vendor
Pengutronix
Product
barebox
Classifications
CWE-125, CAPEC-540, T1499.004
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 11, 2026CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=2026.04.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Pengutronix · bareboxversion=0 <=2026.04.0

Published CVSS scores

6.5VulnCheckCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
7.1VulnCheckCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
CAPEC-540Overread Buffers
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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