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
49%
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 6× in last 7d / 33× 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 230 total refreshes for this CVE.

  1. 2026-09-13 16:47 UTCEPSS rescore
  2. 2026-09-12 15:01 UTCEPSS rescore
  3. 2026-09-11 14:52 UTCEPSS rescore
  4. 2026-09-11 14:23 UTCOSV refresh
  5. 2026-09-10 09:34 UTCEPSS rescore
  6. 2026-09-08 22:00 UTCEPSS rescore
  7. 2026-09-07 16:01 UTCEPSS rescore
  8. 2026-09-06 13:47 UTCEPSS rescore
  9. 2026-09-06 13:47 UTCEPSS rescore
  10. 2026-09-04 05:06 UTCEPSS rescore
  11. 2026-09-02 14:11 UTCEPSS rescore
  12. 2026-09-01 13:53 UTCEPSS rescore
  13. 2026-09-01 04:39 UTCEPSS rescore
  14. 2026-09-01 04:39 UTCEPSS rescore
  15. 2026-08-30 19:17 UTCEPSS rescore
  16. 2026-08-30 01:22 UTCEPSS rescore
  17. 2026-08-28 21:41 UTCEPSS rescore
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-24 14:17 UTCEPSS rescore
  22. 2026-08-23 19:00 UTCEG score recompute
  23. 2026-08-23 19:00 UTCGHSA enrichment
  24. 2026-08-23 00:19 UTCEPSS rescore
  25. 2026-08-21 23:49 UTCEPSS rescore
Show 75 more
  1. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 22:55 UTCEPSS rescore
  3. 2026-08-19 17:03 UTCEPSS rescore
  4. 2026-08-18 13:48 UTCEPSS rescore
  5. 2026-08-17 13:47 UTCEPSS rescore
  6. 2026-08-17 11:30 UTCEG score recompute
  7. 2026-08-17 11:30 UTCGHSA enrichment
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 04:33 UTCEG score recompute
  10. 2026-08-16 04:33 UTCGHSA enrichment
  11. 2026-08-16 02:14 UTCEPSS rescore
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 16:15 UTCGHSA enrichment
  14. 2026-08-14 03:07 UTCEG score recompute
  15. 2026-08-14 03:07 UTCGHSA enrichment
  16. 2026-08-13 22:00 UTCEPSS rescore
  17. 2026-08-13 05:59 UTCGHSA enrichment
  18. 2026-08-12 16:43 UTCEG score recompute
  19. 2026-08-12 16:43 UTCGHSA enrichment
  20. 2026-08-12 13:50 UTCEPSS rescore
  21. 2026-08-11 15:51 UTCEG score recompute
  22. 2026-08-11 15:51 UTCGHSA enrichment
  23. 2026-08-11 13:42 UTCEPSS rescore
  24. 2026-08-11 01:16 UTCEG score recompute
  25. 2026-08-11 01:16 UTCGHSA enrichment
  26. 2026-08-11 00:00 UTCEPSS rescore
  27. 2026-08-10 04:38 UTCGHSA enrichment
  28. 2026-08-09 15:31 UTCEG score recompute
  29. 2026-08-09 15:31 UTCGHSA enrichment
  30. 2026-08-09 13:46 UTCEPSS rescore
  31. 2026-08-09 02:23 UTCEG score recompute
  32. 2026-08-09 02:23 UTCGHSA enrichment
  33. 2026-08-08 16:37 UTCEPSS rescore
  34. 2026-08-08 03:58 UTCEG score recompute
  35. 2026-08-08 03:58 UTCGHSA enrichment
  36. 2026-08-07 14:50 UTCGHSA enrichment
  37. 2026-08-07 01:43 UTCEG score recompute
  38. 2026-08-07 01:43 UTCGHSA enrichment
  39. 2026-08-06 13:46 UTCEPSS rescore
  40. 2026-08-06 11:15 UTCGHSA enrichment
  41. 2026-08-05 22:07 UTCEG score recompute
  42. 2026-08-05 22:07 UTCGHSA enrichment
  43. 2026-08-05 19:17 UTCEPSS rescore
  44. 2026-08-04 15:10 UTCEPSS rescore
  45. 2026-08-03 19:30 UTCEG score recompute
  46. 2026-08-03 19:30 UTCGHSA enrichment
  47. 2026-08-03 10:36 UTCEPSS rescore
  48. 2026-08-03 04:56 UTCGHSA enrichment
  49. 2026-08-02 15:48 UTCGHSA enrichment
  50. 2026-08-02 02:40 UTCEG score recompute
  51. 2026-08-02 02:40 UTCGHSA enrichment
  52. 2026-08-02 02:26 UTCEPSS rescore
  53. 2026-08-01 04:16 UTCEPSS rescore
  54. 2026-07-30 16:27 UTCEPSS rescore
  55. 2026-07-30 01:30 UTCEPSS rescore
  56. 2026-07-28 15:36 UTCEPSS rescore
  57. 2026-07-26 14:54 UTCEPSS rescore
  58. 2026-07-26 14:54 UTCEPSS rescore
  59. 2026-07-25 14:18 UTCEPSS rescore
  60. 2026-07-25 14:17 UTCEPSS rescore
  61. 2026-07-24 14:17 UTCEPSS rescore
  62. 2026-07-23 14:18 UTCEPSS rescore
  63. 2026-07-23 14:18 UTCEPSS rescore
  64. 2026-07-23 03:08 UTCEG score recompute
  65. 2026-07-22 14:08 UTCEPSS rescore
  66. 2026-07-22 14:08 UTCEPSS rescore
  67. 2026-07-21 15:24 UTCEPSS rescore
  68. 2026-07-21 15:24 UTCEPSS rescore
  69. 2026-07-20 17:08 UTCEPSS rescore
  70. 2026-07-20 17:08 UTCEPSS rescore
  71. 2026-07-19 14:31 UTCEPSS rescore
  72. 2026-07-19 14:31 UTCEPSS rescore
  73. 2026-07-19 02:29 UTCEPSS rescore
  74. 2026-07-18 10:04 UTCEPSS rescore
  75. 2026-07-18 10:04 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 51.3% 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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