CVE-2026-29007Public exploitNetwork attack vector

Network-boot interruption via oversized TCP header

Published Jul 8, 2026 · Updated Jul 8, 2026

Out-of-bounds read in U-Boot 2026.04-rc3 and earlier allows remote attackers to interrupt network boot with a malformed TCP header. tcp_rx_state_machine trusts a TCP data offset larger than the IP total length, causing tcp_parse_options to read beyond the segment and update connection state from adjacent memory. Reachability requires CONFIG_PROT_TCP and an established TCP transfer during network boot; local-network packet injection can destabilize TCP calculations, while code execution is not established.

CVSS severity6.9
Medium
EPSS probability0.67%
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 U-Boot 2026.04-rc3 and earlier allows remote attackers to interrupt network boot with a malformed TCP header. tcp_rx_state_machine trusts a TCP data offset larger than the IP total length, causing tcp_parse_options to read beyond the segment and update connection state from adjacent memory. Reachability requires CONFIG_PROT_TCP and an established TCP transfer during network boot; local-network packet injection can destabilize TCP calculations, while code execution is not established.

The record

CVE
CVE-2026-29007
Published
Jul 8, 2026
Updated
Jul 8, 2026
Vendor
DENX Software Engineering GmbH
Product
U-Boot
Classifications
CWE-125, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 8, 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-rc3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

DENX Software Engineering GmbH · U-Bootversion=0 <=2026.04-rc3

Published CVSS scores

5.3VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
6.9VulnCheckCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
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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