CVE-2026-29007

U-Boot 2026.04-rc3 Out-of-Bounds Read in tcp_rx_state_machine via tcp.c

MEDIUM
5.3
CVSS Score
Published: July 8, 2026 at 04:11 PM UTC
Updated: July 22, 2026 at 06:44 PM UTC
2 products affected across 2 vendorsU BootU Boot

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.7%
SSVC
No known exploit

Description

U-Boot through 2026.04-rc3 contains an out-of-bounds read vulnerability in tcp_rx_state_machine() (net/tcp.c) when CONFIG_PROT_TCP is enabled, allowing remote attackers to read beyond TCP segment boundaries by crafting a malicious packet with a mismatched IP total length and TCP data offset field. Attackers can send a packet with an IP total length of 40 bytes and a TCP data offset claiming 60 bytes of header to cause tcp_parse_options() to read 40 bytes past the end of the TCP segment, potentially corrupting connection state variables such as rmt_win_scale and rmt_timestamp to disrupt TCP window calculations.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 2026.04v < 2026.042026.04 rc12026.04 rc22026.04 rc3
Affected range stops below 2026.04, so it looks safe — our inference, not a vendor statement
v ≤ 2026.04-rc3

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (4)

Issue TrackingMailing ListThird Party Advisory
Source: cverecord
https://lists.denx.de/pipermail/u-boot/2026-May/617853.html
Product
Source: cverecord
https://u-boot.org/
Technical DescriptionExploitThird Party Advisory
Source: cverecord
https://y637f9qq2x.com/posts/u-boot-tcp-nfs-vulns/

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusANALYZED
CWE
CWE-125

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