CVE-2026-86543

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreHIGH confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-09-08. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 3 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

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

knowns versions before 0.30.0 serve the management API without authentication on all network interfaces by default, with no password required on fresh installations. Attackers can access the unauthenticated /api/tunnel/start endpoint to provision a public tunnel and republish the API at a publicly accessible address.

CVSS v3
9.8
EG Score
9.8(high)
EG Risk
59(Track)
EG Risk 59/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
38%
KEV
Not listed

Published

September 7, 2026

Last Modified

September 14, 2026

Advisory Details (7)

Auto-updated Sep 14, 2026
Patch available. Sources: github_release, github, github_commit.
generic

knowns before 0.30.0 Unauthenticated Management API Exposure | Advisories | VulnCheck

https://www.vulncheck.com/advisories/knowns-before-0.30.0-unauthenticated-management-api-exposure
github Patch Available

Insecure Default Configuration leads to Unauthenticated Management API Exposure on All Interfaces · Advisory · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/security/advisories/GHSA-fc85-99vc-9c75
github_release Patch Available

v0.30.0

Patch available: knowns-dev/knowns v0.30.0

https://github.com/knowns-dev/knowns/releases/tag/v0.30.0
github_commit

commit 878a02cb7cc1 (knowns-dev/knowns)

Fix landed in knowns-dev/knowns commit 878a02cb7cc1 — awaiting tagged release

https://github.com/knowns-dev/knowns/commit/878a02cb7cc14f0a592fdfda7a520af3cac500fb
generic

knowns/internal/server/routes/tunnel.go at v0.29.1 · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/routes/tunnel.go#L26-L38
generic

knowns/internal/server/auth.go at v0.29.1 · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/server/auth.go#L80-L86
generic

knowns/internal/cli/browser.go at v0.29.1 · knowns-dev/knowns · GitHub

https://github.com/knowns-dev/knowns/blob/v0.29.1/internal/cli/browser.go#L193-L200

Vendor Advisories for CVE-2026-86543(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 61× in last 7d / 115× 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 115 total refreshes for this CVE.

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

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-86543?
CVE-2026-86543 is a critical vulnerability published on September 7, 2026. knowns versions before 0.30.0 serve the management API without authentication on all network interfaces by default, with no password required on fresh installations. Attackers can access the unauthenticated /api/tunnel/start endpoint to provision a public tunnel and republish the API at a publicly…
When was CVE-2026-86543 disclosed?
CVE-2026-86543 was first published in the National Vulnerability Database on September 7, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-86543 actively exploited?
CVE-2026-86543 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 62.0% of all scored CVEs.
What is the CVSS score of CVE-2026-86543?
CVE-2026-86543 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-86543?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-86543, 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.

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