CVE-2026-29008

HIGHPre-NVD 7.57.5—
EchelonGraph scoreHIGH confidence

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-07-08. a secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

U-Boot through 2026.04-rc3 contains an integer underflow vulnerability in the tcp_rx_state_machine() function (net/tcp.c) that allows a network-adjacent attacker to crash the bootloader by sending a malformed TCP SYN+ACK packet with a manipulated data offset field causing payload_len to become negative. When the TCP_SYN_SENT handler calls tcp_rx_user_data() without invoking tcp_seg_in_wnd() validation, the negative payload_len is implicitly converted to a large unsigned integer (e.g., 0xFFFFFFD8) and passed to memcpy() in store_block(), causing an immediate crash that prevents device boot and may enable memory corruption when CONFIG_LMB is disabled.

CVSS v3
7.5
EG Score
7.5(high)
EG Risk
49(Track)
EG Risk 49/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS
39.5%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 22, 2026

Advisory Details (3)

Auto-updated Jul 8, 2026
No patch confirmed yet.
generic

U-Boot 2026.04-rc3 Integer Underflow DoS via tcp_rx_state_machine() | Advisories | VulnCheck

https://www.vulncheck.com/advisories/u-boot-rc3-integer-underflow-dos-via-tcp-rx-state-machine
generic

Das U-Boot: The Universal Boot Loader

https://u-boot.org/
generic

Coordinated Vulnerability Disclosure - U-Boot Multiple Vulnerabilities (3)

https://lists.denx.de/pipermail/u-boot/2026-May/617853.html

Vendor Advisories for CVE-2026-29008(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 17× in last 7d / 46× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-23 14:18 UTCEPSS rescore
  2. 2026-07-23 14:18 UTCEPSS rescore
  3. 2026-07-23 03:08 UTCEG score recompute
  4. 2026-07-22 14:08 UTCEPSS rescore
  5. 2026-07-22 14:08 UTCEPSS rescore
  6. 2026-07-21 15:24 UTCEPSS rescore
  7. 2026-07-21 15:24 UTCEPSS rescore
  8. 2026-07-20 17:08 UTCEPSS rescore
  9. 2026-07-20 17:08 UTCEPSS rescore
  10. 2026-07-19 14:31 UTCEPSS rescore
  11. 2026-07-19 14:31 UTCEPSS rescore
  12. 2026-07-19 02:29 UTCEPSS rescore
  13. 2026-07-18 10:04 UTCEPSS rescore
  14. 2026-07-18 10:04 UTCEPSS rescore
  15. 2026-07-17 02:20 UTCGHSA enrichment
  16. 2026-07-16 17:03 UTCEPSS rescore
  17. 2026-07-16 17:03 UTCEPSS rescore
  18. 2026-07-16 15:08 UTCGHSA enrichment
  19. 2026-07-16 03:56 UTCGHSA enrichment
  20. 2026-07-15 16:57 UTCEPSS rescore
  21. 2026-07-15 16:57 UTCEPSS rescore
  22. 2026-07-15 16:43 UTCGHSA enrichment
  23. 2026-07-15 05:31 UTCGHSA enrichment
  24. 2026-07-15 02:00 UTCEPSS rescore
  25. 2026-07-15 02:00 UTCEPSS rescore
Show 21 more
  1. 2026-07-14 18:15 UTCGHSA enrichment
  2. 2026-07-14 07:02 UTCGHSA enrichment
  3. 2026-07-13 22:30 UTCEPSS rescore
  4. 2026-07-13 19:49 UTCGHSA enrichment
  5. 2026-07-13 08:36 UTCGHSA enrichment
  6. 2026-07-13 06:13 UTCEPSS rescore
  7. 2026-07-13 06:13 UTCEPSS rescore
  8. 2026-07-12 21:22 UTCGHSA enrichment
  9. 2026-07-12 10:09 UTCGHSA enrichment
  10. 2026-07-12 05:46 UTCEPSS rescore
  11. 2026-07-11 22:56 UTCGHSA enrichment
  12. 2026-07-11 11:44 UTCGHSA enrichment
  13. 2026-07-11 08:27 UTCEPSS rescore
  14. 2026-07-11 00:31 UTCGHSA enrichment
  15. 2026-07-10 13:18 UTCGHSA enrichment
  16. 2026-07-10 02:05 UTCGHSA enrichment
  17. 2026-07-09 19:10 UTCEPSS rescore
  18. 2026-07-09 14:50 UTCGHSA enrichment
  19. 2026-07-09 03:37 UTCGHSA enrichment
  20. 2026-07-08 16:24 UTCEG score recompute
  21. 2026-07-08 16:24 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-29008?
CVE-2026-29008 is a high vulnerability published on July 8, 2026. U-Boot through 2026.04-rc3 contains an integer underflow vulnerability in the tcprxstatemachine() function (net/tcp.c) that allows a network-adjacent attacker to crash the bootloader by sending a malformed TCP SYN+ACK packet with a manipulated data offset field causing payloadlen to become…
When was CVE-2026-29008 disclosed?
CVE-2026-29008 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 22, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-29008 actively exploited?
CVE-2026-29008 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 39.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-29008?
CVE-2026-29008 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-29008?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-29008, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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