CVE-2026-71254

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-08-05. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

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

nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus server-side handle_read_file_record function (FC 0x14, Read File Record) in nanomodbus.c. The function validates that the total request size does not exceed 245 bytes and that each sub-request's record_length is at most 124, but it never validates the CUMULATIVE response size across all sub-requests before processing them.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

August 5, 2026

Last Modified

August 26, 2026

Advisory Details (2)

Auto-updated Sep 16, 2026
No patch confirmed yet.
generic

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

https://github.com/debevv/nanoMODBUS/blob/master/nanomodbus.c
generic

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

https://github.com/debevv/nanoMODBUS

Vendor Advisories for CVE-2026-71254(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 41× in last 7d / 177× 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 314 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-71254?
CVE-2026-71254 is a critical vulnerability published on August 5, 2026. nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus server-side handlereadfilerecord function (FC 0x14, Read File Record) in nanomodbus.c. The function validates that the total request size does not exceed 245 bytes and that each sub-request's recordlength is at most 124, but…
When was CVE-2026-71254 disclosed?
CVE-2026-71254 was first published in the National Vulnerability Database on August 5, 2026, with the most recent update on August 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-71254 actively exploited?
CVE-2026-71254 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 76.3% of all scored CVEs.
What is the CVSS score of CVE-2026-71254?
CVE-2026-71254 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-71254?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-71254, 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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