CVE-2026-29008

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM 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
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 7.5Exploit: None knownExposed: 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(medium)
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%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
52%
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.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
u-boot2021.01+dfsg-5 ... 2025.01-3.2 (53 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
u-boot2023.01+dfsg-2 ... 2025.01-3.2 (24 versions)——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
u-boot2025.01-3, 2025.01-3+deb13u1, 2025.01-3.1, 2025.01-3.2——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
u-boot2025.01-3, 2025.01-3.1, 2025.01-3.2——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 67× 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.

Showing the most recent 100 of 218 total refreshes for this CVE.

  1. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-18 05:43 UTCEG score recompute
  4. 2026-09-18 05:43 UTCGHSA enrichment
  5. 2026-09-17 19:30 UTCEPSS rescore
  6. 2026-09-16 14:08 UTCEPSS rescore
  7. 2026-09-16 05:15 UTCEPSS rescore
  8. 2026-09-14 11:15 UTCGHSA enrichment
  9. 2026-09-13 23:49 UTCEG score recompute
  10. 2026-09-13 23:49 UTCGHSA enrichment
  11. 2026-09-13 16:47 UTCEPSS rescore
  12. 2026-09-13 08:25 UTCEG score recompute
  13. 2026-09-13 08:24 UTCGHSA enrichment
  14. 2026-09-12 15:01 UTCEPSS rescore
  15. 2026-09-12 14:48 UTCGHSA enrichment
  16. 2026-09-12 03:35 UTCEG score recompute
  17. 2026-09-12 03:35 UTCGHSA enrichment
  18. 2026-09-11 14:52 UTCEPSS rescore
  19. 2026-09-10 09:34 UTCEPSS rescore
  20. 2026-09-08 22:00 UTCEPSS rescore
  21. 2026-09-07 16:01 UTCEPSS rescore
  22. 2026-09-06 14:03 UTCEG score recompute
  23. 2026-09-06 14:03 UTCGHSA enrichment
  24. 2026-09-06 13:47 UTCEPSS rescore
  25. 2026-09-06 13:47 UTCEPSS rescore
Show 75 more
  1. 2026-09-05 22:48 UTCEG score recompute
  2. 2026-09-05 22:48 UTCGHSA enrichment
  3. 2026-09-04 05:06 UTCEPSS rescore
  4. 2026-09-02 14:11 UTCEPSS rescore
  5. 2026-09-01 13:53 UTCEPSS rescore
  6. 2026-09-01 04:39 UTCEPSS rescore
  7. 2026-09-01 04:39 UTCEPSS rescore
  8. 2026-08-30 19:17 UTCEPSS rescore
  9. 2026-08-30 18:44 UTCGHSA enrichment
  10. 2026-08-30 07:30 UTCEG score recompute
  11. 2026-08-30 07:30 UTCGHSA enrichment
  12. 2026-08-30 01:22 UTCEPSS rescore
  13. 2026-08-28 21:41 UTCEPSS rescore
  14. 2026-08-27 21:50 UTCEG score recompute
  15. 2026-08-27 21:50 UTCGHSA enrichment
  16. 2026-08-27 14:25 UTCEPSS rescore
  17. 2026-08-27 01:29 UTCEG score recompute
  18. 2026-08-27 01:29 UTCGHSA enrichment
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-26 08:24 UTCEG score recompute
  21. 2026-08-26 08:24 UTCGHSA enrichment
  22. 2026-08-25 13:49 UTCEPSS rescore
  23. 2026-08-25 11:40 UTCGHSA enrichment
  24. 2026-08-24 23:49 UTCEG score recompute
  25. 2026-08-24 23:49 UTCGHSA enrichment
  26. 2026-08-24 14:17 UTCEPSS rescore
  27. 2026-08-24 12:37 UTCEG score recompute
  28. 2026-08-24 12:37 UTCGHSA enrichment
  29. 2026-08-24 00:48 UTCGHSA enrichment
  30. 2026-08-23 13:36 UTCGHSA enrichment
  31. 2026-08-23 02:23 UTCEG score recompute
  32. 2026-08-23 02:23 UTCGHSA enrichment
  33. 2026-08-23 00:19 UTCEPSS rescore
  34. 2026-08-22 15:02 UTCGHSA enrichment
  35. 2026-08-22 03:47 UTCEG score recompute
  36. 2026-08-22 03:47 UTCGHSA enrichment
  37. 2026-08-21 23:49 UTCEPSS rescore
  38. 2026-08-21 15:11 UTCGHSA enrichment
  39. 2026-08-21 03:59 UTCEG score recompute
  40. 2026-08-21 03:59 UTCGHSA enrichment
  41. 2026-08-20 22:55 UTCEPSS rescore
  42. 2026-08-20 22:55 UTCEPSS rescore
  43. 2026-08-20 15:37 UTCGHSA enrichment
  44. 2026-08-20 01:59 UTCEG score recompute
  45. 2026-08-20 01:59 UTCGHSA enrichment
  46. 2026-08-19 17:03 UTCEPSS rescore
  47. 2026-08-19 09:48 UTCGHSA enrichment
  48. 2026-08-18 22:28 UTCEG score recompute
  49. 2026-08-18 22:28 UTCGHSA enrichment
  50. 2026-08-18 13:48 UTCEPSS rescore
  51. 2026-08-18 10:50 UTCGHSA enrichment
  52. 2026-08-17 22:29 UTCEG score recompute
  53. 2026-08-17 22:29 UTCGHSA enrichment
  54. 2026-08-17 13:47 UTCEPSS rescore
  55. 2026-08-17 08:21 UTCGHSA enrichment
  56. 2026-08-16 21:09 UTCEG score recompute
  57. 2026-08-16 21:09 UTCGHSA enrichment
  58. 2026-08-16 14:56 UTCEPSS rescore
  59. 2026-08-16 09:57 UTCEG score recompute
  60. 2026-08-16 09:57 UTCGHSA enrichment
  61. 2026-08-16 02:14 UTCEPSS rescore
  62. 2026-08-15 22:45 UTCGHSA enrichment
  63. 2026-08-15 11:32 UTCEG score recompute
  64. 2026-08-15 11:32 UTCGHSA enrichment
  65. 2026-08-15 01:30 UTCEPSS rescore
  66. 2026-08-15 00:19 UTCGHSA enrichment
  67. 2026-08-14 13:07 UTCGHSA enrichment
  68. 2026-08-14 01:54 UTCEG score recompute
  69. 2026-08-14 01:54 UTCGHSA enrichment
  70. 2026-08-13 22:00 UTCEPSS rescore
  71. 2026-08-13 14:42 UTCGHSA enrichment
  72. 2026-08-13 03:29 UTCGHSA enrichment
  73. 2026-08-12 16:17 UTCEG score recompute
  74. 2026-08-12 16:17 UTCGHSA enrichment
  75. 2026-08-12 13:50 UTCEPSS rescore

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 1% probability of exploitation in the next 30 days, which ranks it in the top 48.1% of all scored CVEs.
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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