CVE-2026-56789

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

Score 6.5 from GitHub Security Advisory (severity: HIGH) published 2026-06-25. a secondary CVSS source baseline 6.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Elevated
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: 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 a heap buffer overflow vulnerability in the readrnxobsb function in src/rinex.c that allows attackers to trigger memory corruption by failing to clamp satellite count values from RINEX epoch headers. Attackers can craft malicious RINEX files declaring more than 64 satellites per epoch to cause heap buffer overflow writes and out-of-bounds stack reads, crashing RTKLIB-based applications including rnx2rtkp and RTKPOST.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
45(Track)
EG Risk 45/100SSVC: 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
Severity65% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
36%
KEV
Not listed

Published

June 25, 2026

Last Modified

July 14, 2026

Advisory Details (2)

Auto-updated Jun 25, 2026
🔬 Proof of concept available. No patch confirmed yet.
generic

RTKLIB 2.4.3 - Heap Buffer Overflow and Stack Read via Oversized RINEX Epoch Satellite Count | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rtklib-heap-buffer-overflow-and-stack-read-via-oversized-rinex-epoch-satellite-count
generic🟡 PoC Available

Out-of-Bounds Access in RTKLIB `readrnxobsb` via Oversized RINEX Epoch Satellite Count · Issue #796 · tomojitakasu/RTKLIB · GitHub

https://github.com/tomojitakasu/RTKLIB/issues/796

Vendor Advisories for CVE-2026-56789(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 / 51× 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 168 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 19:31 UTCEG score recompute
  11. 2026-08-30 19:31 UTCGHSA enrichment
  12. 2026-08-30 19:17 UTCEPSS rescore
  13. 2026-08-30 01:22 UTCEPSS rescore
  14. 2026-08-28 21:42 UTCEPSS rescore
  15. 2026-08-27 23:17 UTCEG score recompute
  16. 2026-08-27 23:17 UTCGHSA enrichment
  17. 2026-08-27 14:25 UTCEPSS rescore
  18. 2026-08-26 14:46 UTCEPSS rescore
  19. 2026-08-25 13:49 UTCEPSS rescore
  20. 2026-08-24 13:09 UTCEG score recompute
  21. 2026-08-24 13:09 UTCGHSA enrichment
  22. 2026-08-23 10:27 UTCEG score recompute
  23. 2026-08-23 10:27 UTCGHSA enrichment
  24. 2026-08-23 00:19 UTCEPSS rescore
  25. 2026-08-22 10:01 UTCEG score recompute
Show 75 more
  1. 2026-08-22 10:00 UTCGHSA enrichment
  2. 2026-08-21 23:49 UTCEPSS rescore
  3. 2026-08-21 07:26 UTCEG score recompute
  4. 2026-08-21 07:26 UTCGHSA enrichment
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-20 07:02 UTCEG score recompute
  7. 2026-08-20 07:02 UTCGHSA enrichment
  8. 2026-08-19 17:04 UTCEPSS rescore
  9. 2026-08-19 01:14 UTCEG score recompute
  10. 2026-08-19 01:14 UTCGHSA enrichment
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 13:47 UTCEPSS rescore
  13. 2026-08-17 13:10 UTCEG score recompute
  14. 2026-08-17 13:10 UTCGHSA enrichment
  15. 2026-08-16 14:56 UTCEPSS rescore
  16. 2026-08-16 12:47 UTCEG score recompute
  17. 2026-08-16 12:47 UTCGHSA enrichment
  18. 2026-08-16 02:14 UTCEPSS rescore
  19. 2026-08-15 12:23 UTCEG score recompute
  20. 2026-08-15 12:23 UTCGHSA enrichment
  21. 2026-08-15 01:30 UTCEPSS rescore
  22. 2026-08-14 11:59 UTCEG score recompute
  23. 2026-08-14 11:59 UTCGHSA enrichment
  24. 2026-08-13 22:00 UTCEPSS rescore
  25. 2026-08-13 11:34 UTCEG score recompute
  26. 2026-08-13 11:34 UTCGHSA enrichment
  27. 2026-08-12 13:51 UTCEPSS rescore
  28. 2026-08-12 11:11 UTCEG score recompute
  29. 2026-08-12 11:11 UTCGHSA enrichment
  30. 2026-08-11 10:46 UTCEG score recompute
  31. 2026-08-11 10:46 UTCGHSA enrichment
  32. 2026-08-11 00:00 UTCEPSS rescore
  33. 2026-08-10 10:22 UTCEG score recompute
  34. 2026-08-10 10:22 UTCGHSA enrichment
  35. 2026-08-09 13:46 UTCEPSS rescore
  36. 2026-08-09 09:58 UTCEG score recompute
  37. 2026-08-09 09:58 UTCGHSA enrichment
  38. 2026-08-08 16:37 UTCEPSS rescore
  39. 2026-08-08 09:35 UTCEG score recompute
  40. 2026-08-08 09:35 UTCGHSA enrichment
  41. 2026-08-07 09:11 UTCEG score recompute
  42. 2026-08-07 09:11 UTCGHSA enrichment
  43. 2026-08-06 13:47 UTCEPSS rescore
  44. 2026-08-06 08:47 UTCEG score recompute
  45. 2026-08-06 08:47 UTCGHSA enrichment
  46. 2026-08-05 19:17 UTCEPSS rescore
  47. 2026-08-05 08:23 UTCEG score recompute
  48. 2026-08-05 08:23 UTCGHSA enrichment
  49. 2026-08-04 15:10 UTCEPSS rescore
  50. 2026-08-04 10:39 UTCEPSS rescore
  51. 2026-08-04 03:53 UTCEG score recompute
  52. 2026-08-04 03:53 UTCGHSA enrichment
  53. 2026-08-03 10:36 UTCEPSS rescore
  54. 2026-08-03 03:29 UTCGHSA enrichment
  55. 2026-08-02 03:05 UTCEG score recompute
  56. 2026-08-02 03:05 UTCGHSA enrichment
  57. 2026-08-02 02:27 UTCEPSS rescore
  58. 2026-08-01 04:16 UTCEPSS rescore
  59. 2026-08-01 02:40 UTCGHSA enrichment
  60. 2026-07-31 01:11 UTCEG score recompute
  61. 2026-07-31 01:10 UTCGHSA enrichment
  62. 2026-07-30 16:28 UTCEPSS rescore
  63. 2026-07-30 01:30 UTCEPSS rescore
  64. 2026-07-30 01:30 UTCEPSS rescore
  65. 2026-07-30 00:42 UTCGHSA enrichment
  66. 2026-07-28 21:05 UTCEG score recompute
  67. 2026-07-28 21:04 UTCGHSA enrichment
  68. 2026-07-28 15:37 UTCEPSS rescore
  69. 2026-07-27 17:16 UTCEG score recompute
  70. 2026-07-27 17:16 UTCGHSA enrichment
  71. 2026-07-27 14:14 UTCEPSS rescore
  72. 2026-07-26 14:55 UTCEG score recompute
  73. 2026-07-26 14:55 UTCGHSA enrichment
  74. 2026-07-26 14:54 UTCEPSS rescore
  75. 2026-07-26 14:54 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-56789?
CVE-2026-56789 is a medium vulnerability published on June 25, 2026. RTKLIB through 2.4.3 contains a heap buffer overflow vulnerability in the readrnxobsb function in src/rinex.c that allows attackers to trigger memory corruption by failing to clamp satellite count values from RINEX epoch headers. Attackers can craft malicious RINEX files declaring more than 64…
When was CVE-2026-56789 disclosed?
CVE-2026-56789 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-2026-56789 actively exploited?
CVE-2026-56789 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 64.4% of all scored CVEs.
What is the CVSS score of CVE-2026-56789?
CVE-2026-56789 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-56789?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56789, 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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