U-Boot 2026.04-rc3 Out-of-Bounds Read in tcp_rx_state_machine via tcp.c (CVE-2026-29007) | HOL Guard CVE

Medium · CVSS 5.3CVE-2026-29007

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

Answer in brief

CVE-2026-29007 records a Medium severity (CVSS 5.3) vulnerability in U-Boot 2026.04-rc3 Out-of-Bounds Read in tcp_rx_state_machine via tcp.c. The current sources do not mark it as known exploited. The current feed maps u-boot/u-boot (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jul 8, 2026Updated Jul 14, 2026Source checked Sep 19, 2026First seen by HOL Jul 8, 2026Material review Jul 14, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps u-boot/u-boot (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
u-boot/u-bootgeneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for u-boot/u-boot.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 8, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.