CVE-2026-71255

HIGHPre-NVD 8.68.6—
EchelonGraph scoreHIGH confidence

Score 8.6 from GitHub Security Advisory (severity: HIGH) published 2026-08-05. a secondary CVSS source baseline 8.6; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
8.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.6Exploit: 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 client-side recv_read_device_identification_res function (FC 0x2B/MEI 0x0E, Read Device Identification) in nanomodbus.c. The server-supplied object_length field (0-246) is validated only against the remaining PDU size (res_size_left) and is never validated against the caller-supplied buffers_length parameter.

CVSS v3
8.6
EG Score
8.6(high)
EG Risk
54(Track)
EG Risk 54/100SSVC: 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
Severity86% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
13%
KEV
Not listed

Published

August 5, 2026

Last Modified

August 10, 2026

Advisory Details (2)

Auto-updated Aug 5, 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-2026-71255(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 32× in last 7d / 76× 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. 2026-08-21 05:47 UTCEG score recompute
  2. 2026-08-21 05:47 UTCGHSA enrichment
  3. 2026-08-20 22:56 UTCEPSS rescore
  4. 2026-08-20 18:09 UTCGHSA enrichment
  5. 2026-08-20 06:30 UTCGHSA enrichment
  6. 2026-08-19 18:53 UTCEG score recompute
  7. 2026-08-19 18:53 UTCGHSA enrichment
  8. 2026-08-19 17:04 UTCEPSS rescore
  9. 2026-08-19 06:24 UTCGHSA enrichment
  10. 2026-08-18 18:48 UTCEG score recompute
  11. 2026-08-18 18:48 UTCGHSA enrichment
  12. 2026-08-18 13:49 UTCEPSS rescore
  13. 2026-08-18 13:49 UTCEPSS rescore
  14. 2026-08-18 07:10 UTCGHSA enrichment
  15. 2026-08-17 19:32 UTCEG score recompute
  16. 2026-08-17 19:32 UTCGHSA enrichment
  17. 2026-08-17 13:47 UTCEPSS rescore
  18. 2026-08-17 07:03 UTCGHSA enrichment
  19. 2026-08-16 19:26 UTCEG score recompute
  20. 2026-08-16 19:26 UTCGHSA enrichment
  21. 2026-08-16 14:56 UTCEPSS rescore
  22. 2026-08-16 14:56 UTCEPSS rescore
  23. 2026-08-16 07:44 UTCEG score recompute
  24. 2026-08-16 07:44 UTCGHSA enrichment
  25. 2026-08-16 02:15 UTCEPSS rescore
Show 51 more
  1. 2026-08-15 20:08 UTCGHSA enrichment
  2. 2026-08-15 08:31 UTCEG score recompute
  3. 2026-08-15 08:31 UTCGHSA enrichment
  4. 2026-08-15 01:31 UTCEPSS rescore
  5. 2026-08-14 20:54 UTCGHSA enrichment
  6. 2026-08-14 09:18 UTCEG score recompute
  7. 2026-08-14 09:18 UTCGHSA enrichment
  8. 2026-08-13 22:00 UTCEPSS rescore
  9. 2026-08-13 21:41 UTCGHSA enrichment
  10. 2026-08-13 10:05 UTCGHSA enrichment
  11. 2026-08-12 22:28 UTCEG score recompute
  12. 2026-08-12 22:28 UTCGHSA enrichment
  13. 2026-08-12 13:51 UTCEPSS rescore
  14. 2026-08-12 10:52 UTCGHSA enrichment
  15. 2026-08-11 23:15 UTCEG score recompute
  16. 2026-08-11 23:15 UTCGHSA enrichment
  17. 2026-08-11 11:38 UTCGHSA enrichment
  18. 2026-08-11 00:02 UTCEG score recompute
  19. 2026-08-11 00:02 UTCGHSA enrichment
  20. 2026-08-11 00:00 UTCEPSS rescore
  21. 2026-08-10 12:24 UTCEG score recompute
  22. 2026-08-10 12:24 UTCGHSA enrichment
  23. 2026-08-10 12:02 UTCGHSA enrichment
  24. 2026-08-10 11:42 UTCGHSA enrichment
  25. 2026-08-10 11:22 UTCEG score recompute
  26. 2026-08-10 11:22 UTCGHSA enrichment
  27. 2026-08-10 09:35 UTCGHSA enrichment
  28. 2026-08-09 21:59 UTCEG score recompute
  29. 2026-08-09 21:59 UTCGHSA enrichment
  30. 2026-08-09 13:47 UTCEPSS rescore
  31. 2026-08-09 10:22 UTCGHSA enrichment
  32. 2026-08-08 22:46 UTCEG score recompute
  33. 2026-08-08 22:46 UTCGHSA enrichment
  34. 2026-08-08 16:37 UTCEPSS rescore
  35. 2026-08-08 11:09 UTCGHSA enrichment
  36. 2026-08-07 23:32 UTCEG score recompute
  37. 2026-08-07 23:32 UTCGHSA enrichment
  38. 2026-08-07 11:55 UTCGHSA enrichment
  39. 2026-08-07 00:19 UTCEG score recompute
  40. 2026-08-07 00:18 UTCGHSA enrichment
  41. 2026-08-06 13:47 UTCEPSS rescore
  42. 2026-08-06 12:41 UTCGHSA enrichment
  43. 2026-08-06 01:05 UTCGHSA enrichment
  44. 2026-08-05 13:28 UTCEG score recompute
  45. 2026-08-05 13:28 UTCGHSA enrichment
  46. 2026-08-05 13:08 UTCEG score recompute
  47. 2026-08-05 13:08 UTCGHSA enrichment
  48. 2026-08-05 12:25 UTCEG score recompute▲ 0.40
  49. 2026-08-05 12:24 UTCNVD updateCVSS v3 → 8.6
  50. 2026-08-05 11:47 UTCEG score recompute
  51. 2026-08-05 11:47 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-71255?
CVE-2026-71255 is a high vulnerability published on August 5, 2026. nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus client-side recvreaddeviceidentificationres function (FC 0x2B/MEI 0x0E, Read Device Identification) in nanomodbus.c. The server-supplied objectlength field (0-246) is validated only against the remaining PDU size (ressizeleft)…
When was CVE-2026-71255 disclosed?
CVE-2026-71255 was first published in the National Vulnerability Database on August 5, 2026, with the most recent update on August 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-71255 actively exploited?
CVE-2026-71255 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 87.2% of all scored CVEs.
What is the CVSS score of CVE-2026-71255?
CVE-2026-71255 has a CVSS v3 base score of 8.6 (NVD).
How do I remediate CVE-2026-71255?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-71255, 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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