CVE-2025-66398

CRITICALNVD 8.89.6▲
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.6 under NVD CVSS v3. EPSS exploit probability: 17.9%, top 3% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this weekElevated
9.6EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 18%CVSS: 8.8Exploit: Elevated riskExposed: 0

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

Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.19.0, an unauthenticated attacker can pollute the internal state (restoreFilePath) of the server via the /skServer/validateBackup endpoint. This allows the attacker to hijack the administrator's "Restore" functionality to overwrite critical server configuration files (e.g., security.json, package.json), leading to account takeover and Remote Code Execution (RCE). Version 2.19.0 patches this vulnerability.

CVSS v3
8.8
EG Score
9.6(medium)
EG Risk
74(Attend)
EG Risk 74/100SSVC: 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
Severity96% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
18%
EPSS %ILE
97%
KEV
Not listed

Published

January 1, 2026

Last Modified

June 17, 2026

Advisory Details (2)

Auto-updated Jul 15, 2026
🔬 Proof of concept available. Patch available. Sources: github_release, github.
github Patch Available🟡 PoC Available

Unauthenticated State Pollution leading to Remote Code Execution (RCE) · Advisory · SignalK/signalk-server · GitHub

https://github.com/SignalK/signalk-server/security/advisories/GHSA-w3x5-7c4c-66p9
github_release Patch Available

v2.19.0

Patch available: SignalK/signalk-server v2.19.0

https://github.com/SignalK/signalk-server/releases/tag/v2.19.0

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
signalk-server—2.19.0—

Weakness Classification(2)

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

Data Freshness Timeline

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

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCjoshuavanderpoll/cve-2025-66398
    First seen Mar 10, 2026

    CVE-2025-66398 — Signal K Server ≤ 2.18.0 RCE PoC

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2025-66398?
CVE-2025-66398 is a critical vulnerability published on January 1, 2026. Signal K Server is a server application that runs on a central hub in a boat. Prior to version 2.19.0, an unauthenticated attacker can pollute the internal state (restoreFilePath) of the server via the /skServer/validateBackup endpoint. This allows the attacker to hijack the administrator's…
When was CVE-2025-66398 disclosed?
CVE-2025-66398 was first published in the National Vulnerability Database on January 1, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2025-66398 actively exploited?
CVE-2025-66398 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 18% probability of exploitation in the next 30 days, which ranks it in the top 3.1% of all scored CVEs.
What is the CVSS score of CVE-2025-66398?
CVE-2025-66398 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.6.
How do I remediate CVE-2025-66398?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2025-66398, 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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