CVE-2026-29972

HIGHNVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-05-08. NVD baseline CVSS 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.2Exploit: None knownExposed: 0

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

nanoMODBUS through v1.22.0 has a stack-based buffer overflow in recv_read_registers_res() in nanomodbus.c. When a client calls nmbs_read_holding_registers() or nmbs_read_input_registers(), the library writes register data from the server response to the caller-provided buffer based on the response's byte_count field before validating that byte_count matches the requested quantity. A malicious Modbus TCP server can send a response with byte_count=250 (125 registers) regardless of the requested quantity, causing up to 248 bytes of attacker-controlled data to overflow the buffer, potentially allowing remote code execution.

CVSS v3
8.2
EG Score
8.2(medium)
EG Risk
52(Track)
EG Risk 52/100SSVC: 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
Severity82% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
47%
KEV
Not listed

Published

May 8, 2026

Last Modified

May 13, 2026

Advisory Details (3)

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

nanoMODBUS/nanomodbus.c at master · debevv/nanoMODBUS · GitHub

https://github.com/debevv/nanoMODBUS/blob/master/nanomodbus.c#L580-L615
generic

GitHub - debevv/nanoMODBUS: A compact MODBUS RTU/TCP C library for embedded/microcontrollers · GitHub

https://github.com/debevv/nanoMODBUS
generic

nanoMODBUS buffer overflow · GitHub

https://gist.github.com/dwilliams27/a4e26fe747c8561d608f7549804bd85f

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 49× 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 149 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-29972?
CVE-2026-29972 is a high vulnerability published on May 8, 2026. nanoMODBUS through v1.22.0 has a stack-based buffer overflow in recvreadregistersres() in nanomodbus.c. When a client calls nmbsreadholdingregisters() or nmbsreadinputregisters(), the library writes register data from the server response to the caller-provided buffer based on the response's…
When was CVE-2026-29972 disclosed?
CVE-2026-29972 was first published in the National Vulnerability Database on May 8, 2026, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-29972 actively exploited?
CVE-2026-29972 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 53.1% of all scored CVEs.
What is the CVSS score of CVE-2026-29972?
CVE-2026-29972 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-29972?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-29972, 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.

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