CVE-2026-11826

HIGHPre-NVD 8.88.8—
EchelonGraph scoreMEDIUM confidence

Score 8.8 from GitHub Security Advisory (severity: HIGH) published 2026-07-18. the CNA's CVSS baseline 8.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
8.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 8.8Exploit: None knownExposed: 0

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

OpenPLC_v3 contains a heap-based buffer overflow in the getData() function in webserver/core/modbus_master.cpp. getData() reads characters between two delimiters into a caller-supplied buffer with no size parameter and no bounds check. In parseConfig() the function is invoked with the 100-byte heap-allocated MB_device.dev_name field. An authenticated attacker with access to the OpenPLC web interface can send a crafted HTTP POST to the /modbus endpoint with an oversized device_name value; the value is persisted to mbconfig.cfg and parsed on load, overflowing dev_name and overwriting adjacent struct fields (protocol at offset 108, dev_address at offset 109, ip_port at offset 210). A 200-byte payload writes 100 bytes past the allocation. The result is heap corruption leading to runtime crash and denial of service of the PLC process control loop, with attacker-controlled overwrite of adjacent configuration fields. The upstream repository was archived on 2026-04-04 and no fix is expected; the vendor has confirmed the issue does not affect OpenPLC Runtime v4.

CVSS v3
8.8
EG Score
8.8(medium)
EG Risk
40(Track)
EG Risk 40/100SSVC: 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
Severity88% × 45%
Exploitation1% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
53%
KEV
Not listed

Published

July 18, 2026

Last Modified

July 28, 2026

Advisory Details (4)

Auto-updated Jul 18, 2026
Upstream fix merged — awaiting tagged release. Sources: github_commit.
generic

OpenPLC_v3 Heap-Based Buffer Overflow in Modbus Master getData() | Advisories | VulnCheck

https://www.vulncheck.com/advisories/openplc-v3-heap-based-buffer-overflow-in-modbus-master-getdata
github_commit

commit b4702061dc14 (thiagoralves/OpenPLC_v3)

Fix landed in thiagoralves/OpenPLC_v3 commit b4702061dc14 — awaiting tagged release

https://github.com/thiagoralves/OpenPLC_v3/commit/b4702061dc14d1024856f71b4543298d77007b88
generic

GitHub - thiagoralves/OpenPLC_v3: OpenPLC Runtime version 3 · GitHub

https://github.com/thiagoralves/OpenPLC_v3
generic

Security Vulnerability Report: Heap Buffer Overflow in getData() — openplcproject/OpenPLC_v3 (CWE-122, CVSS 8.8 HIGH) · GitHub

https://gist.github.com/Shukhrat-03/5cf1825b72e485ef98a32958dfbc611a#security-vulnerability-report

Vendor Advisories for CVE-2026-11826(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 11× 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.

Showing the most recent 100 of 162 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-11826?
CVE-2026-11826 is a high vulnerability published on July 18, 2026. OpenPLCv3 contains a heap-based buffer overflow in the getData() function in webserver/core/modbusmaster.cpp. getData() reads characters between two delimiters into a caller-supplied buffer with no size parameter and no bounds check. In parseConfig() the function is invoked with the 100-byte…
When was CVE-2026-11826 disclosed?
CVE-2026-11826 was first published in the National Vulnerability Database on July 18, 2026, with the most recent update on July 28, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11826 actively exploited?
CVE-2026-11826 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 47.1% of all scored CVEs.
What is the CVSS score of CVE-2026-11826?
CVE-2026-11826 has a CVSS v4.0 base score of 8.8 (CNA self-assessment; NVD's own analysis pending).
How do I remediate CVE-2026-11826?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11826, 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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