CVE-2026-56789

MEDIUMPre-NVD 6.56.5—
EchelonGraph scoreHIGH 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
Trending — 3 sources updated this week
6.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.5Exploit: NoneExposed: 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(high)
EPSS
14.9%
KEV
Not listed

Published

June 25, 2026

Last Modified

June 26, 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.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 24× in last 7d / 39× 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. 2026-07-07 00:26 UTCEG score recompute
  2. 2026-07-07 00:26 UTCGHSA enrichment
  3. 2026-07-06 16:27 UTCEPSS rescore
  4. 2026-07-06 16:27 UTCEPSS rescore
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-06 00:00 UTCEG score recompute
  8. 2026-07-06 00:00 UTCGHSA enrichment
  9. 2026-07-05 02:31 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 23:36 UTCEG score recompute
  12. 2026-07-04 23:35 UTCGHSA enrichment
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-03 23:11 UTCEG score recompute
  16. 2026-07-03 23:11 UTCGHSA enrichment
  17. 2026-07-02 22:44 UTCEG score recompute
  18. 2026-07-02 22:44 UTCGHSA enrichment
  19. 2026-07-01 22:20 UTCEG score recompute
  20. 2026-07-01 22:20 UTCGHSA enrichment
  21. 2026-07-01 15:07 UTCEPSS rescore
  22. 2026-06-30 23:22 UTCEPSS rescore
  23. 2026-06-30 21:51 UTCEG score recompute
  24. 2026-06-30 21:51 UTCGHSA enrichment
  25. 2026-06-29 21:27 UTCEG score recompute
Show 14 more
  1. 2026-06-29 21:27 UTCGHSA enrichment
  2. 2026-06-29 14:06 UTCEPSS rescore
  3. 2026-06-28 21:03 UTCEG score recompute
  4. 2026-06-28 21:03 UTCGHSA enrichment
  5. 2026-06-28 14:07 UTCEPSS rescore
  6. 2026-06-28 04:56 UTCEPSS rescore
  7. 2026-06-28 04:56 UTCEPSS rescore
  8. 2026-06-27 20:39 UTCEG score recompute
  9. 2026-06-27 20:39 UTCGHSA enrichment
  10. 2026-06-27 03:08 UTCEPSS rescore
  11. 2026-06-26 20:13 UTCEG score recompute
  12. 2026-06-26 20:13 UTCGHSA enrichment
  13. 2026-06-25 19:49 UTCEG score recompute
  14. 2026-06-25 19:49 UTCNVD updatefirst tracked

Related CVEs(same CWE)

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 June 26, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-56789 actively exploited?
CVE-2026-56789 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 14.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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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