CVE-2026-56786

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-06-25. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.8Exploit: Elevated riskExposed: 0

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

RTKLIB through 2.4.3 contains an out-of-bounds write vulnerability in decode_type1033 function that fails to clamp length counters to destination buffer size, allowing up to 191-byte overflow into fixed 64-byte descriptor fields. An attacker controlling an NTRIP or serial RTCM3 correction stream can craft a valid CRC-bearing type-1033 message to corrupt adjacent rtcm_t object members, potentially achieving arbitrary code execution or denial of service.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
75(Attend)
EG Risk 75/100SSVC: Attend

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%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
1%
EPSS %ILE
52%
KEV
Not listed

Published

June 25, 2026

Last Modified

July 14, 2026

Advisory Details (2)

Auto-updated Sep 5, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

RTKLIB 2.4.3 - Out-of-bounds Write in decode_type1033 via Crafted RTCM3 Message | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rtklib-out-of-bounds-write-in-decode-type1033-via-crafted-rtcm3-message
generic🟡 PoC Available

Out-of-Bounds Write in RTKLIB decode_type1033 via Unbounded RTCM3 Antenna/Receiver Descriptor Lengths · Issue #799 · tomojitakasu/RTKLIB · GitHub

https://github.com/tomojitakasu/RTKLIB/issues/799

Vendor Advisories for CVE-2026-56786(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
rtklib2.4.3+dfsg1-2.1 ... 2.4.3.b34+dfsg-1 (8 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
rtklib2.4.3.b34+dfsg-1——
Debian:13(1)
PackageVulnerable rangeFixed inDependents
rtklib2.4.3.b34+dfsg-1——
Debian:14(1)
PackageVulnerable rangeFixed inDependents
rtklib2.4.3.b34+dfsg-1——

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 5× in last 7d / 101× 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 409 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-56786?
CVE-2026-56786 is a critical vulnerability published on June 25, 2026. RTKLIB through 2.4.3 contains an out-of-bounds write vulnerability in decodetype1033 function that fails to clamp length counters to destination buffer size, allowing up to 191-byte overflow into fixed 64-byte descriptor fields. An attacker controlling an NTRIP or serial RTCM3 correction stream can…
When was CVE-2026-56786 disclosed?
CVE-2026-56786 was first published in the National Vulnerability Database on June 25, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56786 actively exploited?
CVE-2026-56786 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 48.5% of all scored CVEs.
What is the CVSS score of CVE-2026-56786?
CVE-2026-56786 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-56786?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56786, 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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