CVE-2026-56787

HIGHNVD 7.56.5▼
EchelonGraph scoreHIGH confidence

Score 6.5 from GitHub Security Advisory published 2026-06-25. NVD baseline CVSS 7.5; sources differ by 1.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: 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 an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this vulnerability by sending malicious SSR correction streams over NTRIP or serial connections to cause denial of service or crash RTKLIB rovers and CORS servers.

CVSS v3
7.5
EG Score
6.5(high)
EPSS
24.4%
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 - Off-by-One Out-of-Bounds Read in decode_ssr3 via RTCM3 SSR Message | Advisories | VulnCheck

https://www.vulncheck.com/advisories/rtklib-off-by-one-out-of-bounds-read-in-decode-ssr3-via-rtcm3-ssr-message
generic🟡 PoC Available

Global-Buffer-Overflow in RTKLIB `decode_ssr3` (SSR Code-Bias) via RTCM3 Off-By-One · Issue #798 · tomojitakasu/RTKLIB · GitHub

https://github.com/tomojitakasu/RTKLIB/issues/798

Vendor Advisories for CVE-2026-56787(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 22× in last 7d / 38× 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. 2026-07-06 16:27 UTCEPSS rescore
  2. 2026-07-06 16:27 UTCEPSS rescore
  3. 2026-07-06 14:05 UTCEG score recompute
  4. 2026-07-06 14:05 UTCGHSA enrichment
  5. 2026-07-06 02:23 UTCEPSS rescore
  6. 2026-07-06 02:23 UTCEPSS rescore
  7. 2026-07-05 12:12 UTCEG score recompute
  8. 2026-07-05 12:12 UTCGHSA enrichment
  9. 2026-07-05 02:31 UTCEPSS rescore
  10. 2026-07-05 02:30 UTCEPSS rescore
  11. 2026-07-04 10:24 UTCEG score recompute
  12. 2026-07-04 10:24 UTCGHSA enrichment
  13. 2026-07-04 06:31 UTCEPSS rescore
  14. 2026-07-04 06:31 UTCEPSS rescore
  15. 2026-07-03 08:36 UTCEG score recompute
  16. 2026-07-03 08:36 UTCGHSA enrichment
  17. 2026-07-02 06:48 UTCEG score recompute
  18. 2026-07-02 06:48 UTCGHSA enrichment
  19. 2026-07-01 15:07 UTCEPSS rescore
  20. 2026-07-01 05:00 UTCEG score recompute
  21. 2026-07-01 05:00 UTCGHSA enrichment
  22. 2026-06-30 23:22 UTCEPSS rescore
  23. 2026-06-30 03:12 UTCEG score recompute
  24. 2026-06-30 03:12 UTCGHSA enrichment
  25. 2026-06-29 14:06 UTCEPSS rescore
Show 13 more
  1. 2026-06-29 01:24 UTCEG score recompute
  2. 2026-06-29 01:24 UTCGHSA enrichment
  3. 2026-06-28 14:07 UTCEPSS rescore
  4. 2026-06-28 04:56 UTCEPSS rescore
  5. 2026-06-28 04:56 UTCEPSS rescore
  6. 2026-06-27 23:36 UTCEG score recompute
  7. 2026-06-27 23:36 UTCGHSA enrichment
  8. 2026-06-27 03:08 UTCEPSS rescore
  9. 2026-06-26 21:48 UTCEG score recompute
  10. 2026-06-26 21:48 UTCGHSA enrichment
  11. 2026-06-26 17:41 UTCNVD updateCVSS v3 → 7.5 · severity → HIGH
  12. 2026-06-25 19:49 UTCEG score recompute
  13. 2026-06-25 19:49 UTCNVD updatefirst tracked

Frequently asked(5)

What is CVE-2026-56787?
CVE-2026-56787 is a high vulnerability published on June 25, 2026. RTKLIB through 2.4.3 contains an off-by-one out-of-bounds read vulnerability in the decode_ssr3 function at src/rtcm3.c:1446 that allows remote attackers to trigger a global buffer overflow via crafted RTCM3 SSR messages with attacker-controlled signal mode fields. Remote attackers can exploit this…
When was CVE-2026-56787 disclosed?
CVE-2026-56787 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-2026-56787 actively exploited?
CVE-2026-56787 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 24.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-56787?
CVE-2026-56787 has a CVSS v3 base score of 7.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 6.5.
How do I remediate CVE-2026-56787?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-56787, 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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