CVE-2026-18676

MEDIUMPre-NVD 5.15.1—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 86% 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, secondary
Trending — 3 sources updated this week
5.1EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.1Exploit: None knownExposed: 0

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

The default kuma-cp configuration in Kong Mesh reveals the admin bootstrap token and signing keys to any webpage the operator visits while the control plane is reachable from their browser. Due to a CORS misconfiguration a cross-origin fetch() from a malicious page returns the admin JWT and signing material.

CVSS v3
5.1
EG Score
5.1(medium)
EG Risk
23(Track)
EG Risk 23/100SSVC: 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
Severity51% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
14%
KEV
Not listed

Published

August 12, 2026

Last Modified

August 31, 2026

Advisory Details (8)

Auto-updated Aug 12, 2026
Patch available. Sources: github, github_pr.
generic

Kong Mesh changelog - Kong Mesh | Kong Docs

https://developer.konghq.com/mesh/changelog/
github_pr Patch Available

fix(api-server): harden localhost admin auth (backport of #16416)

Patch available: kumahq/kuma v2.13.5 (PR #16427 merged 2026-04-28)

https://github.com/kumahq/kuma/pull/16427
github_pr Patch Available

fix(api-server): harden localhost admin auth (backport of #16416)

Patch available: kumahq/kuma v2.7.26 (PR #16426 merged 2026-04-28)

https://github.com/kumahq/kuma/pull/16426
github_pr Patch Available

fix(api-server): harden localhost admin auth (backport of #16416)

Patch available: kumahq/kuma v2.11.13 (PR #16425 merged 2026-04-28)

https://github.com/kumahq/kuma/pull/16425
github_pr Patch Available

fix(api-server): harden localhost admin auth (backport of #16416)

Patch available: kumahq/kuma 2.9.15 (PR #16424 merged 2026-04-28)

https://github.com/kumahq/kuma/pull/16424
github_pr Patch Available

fix(api-server): harden localhost admin auth (backport of #16416)

Patch available: kumahq/kuma v2.12.10 (PR #16423 merged 2026-04-28)

https://github.com/kumahq/kuma/pull/16423
github_pr

fix(api-server): harden localhost admin auth

Fix merged in kumahq/kuma PR #16416 on 2026-04-27 — awaiting tagged release

https://github.com/kumahq/kuma/pull/16416
github Patch Available

Default kuma-cp leaks admin token cross-origin via CORS wildcard + LocalhostIsAdmin · Advisory · kumahq/kuma · GitHub

https://github.com/kumahq/kuma/security/advisories/GHSA-3vcp-chfh-f6r2

Vendor Advisories for CVE-2026-18676(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFixed inDependents
github.com/kumahq/kuma—2.13.5—
github.com/kumahq/kuma/v2—2.13.5—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 17× in last 7d / 70× 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. 2026-09-18 19:27 UTCEPSS rescore
  2. 2026-09-18 06:13 UTCEG score recompute
  3. 2026-09-18 06:13 UTCGHSA enrichment
  4. 2026-09-17 03:50 UTCEG score recompute
  5. 2026-09-17 03:50 UTCGHSA enrichment
  6. 2026-09-16 14:07 UTCEPSS rescore
  7. 2026-09-16 05:14 UTCEPSS rescore
  8. 2026-09-16 01:12 UTCEG score recompute
  9. 2026-09-16 01:12 UTCGHSA enrichment
  10. 2026-09-14 21:55 UTCEG score recompute
  11. 2026-09-14 21:55 UTCGHSA enrichment
  12. 2026-09-13 16:46 UTCEPSS rescore
  13. 2026-09-13 14:59 UTCEG score recompute
  14. 2026-09-13 14:59 UTCGHSA enrichment
  15. 2026-09-12 15:00 UTCEPSS rescore
  16. 2026-09-12 12:26 UTCEG score recompute
  17. 2026-09-12 12:26 UTCGHSA enrichment
  18. 2026-09-11 14:52 UTCEPSS rescore
  19. 2026-09-11 10:02 UTCEG score recompute
  20. 2026-09-11 10:02 UTCGHSA enrichment
  21. 2026-09-11 09:36 UTCEPSS rescore
  22. 2026-09-10 09:34 UTCEPSS rescore
  23. 2026-09-10 07:37 UTCGHSA enrichment
  24. 2026-09-09 05:14 UTCEG score recompute
  25. 2026-09-09 05:14 UTCGHSA enrichment
Show 71 more
  1. 2026-09-08 22:00 UTCEPSS rescore
  2. 2026-09-07 16:42 UTCEG score recompute
  3. 2026-09-07 16:42 UTCGHSA enrichment
  4. 2026-09-07 16:01 UTCEPSS rescore
  5. 2026-09-06 13:47 UTCEPSS rescore
  6. 2026-09-06 08:39 UTCEG score recompute
  7. 2026-09-06 08:39 UTCGHSA enrichment
  8. 2026-09-05 06:16 UTCEG score recompute
  9. 2026-09-05 06:16 UTCGHSA enrichment
  10. 2026-09-04 05:06 UTCEPSS rescore
  11. 2026-09-04 03:52 UTCGHSA enrichment
  12. 2026-09-03 01:25 UTCEG score recompute
  13. 2026-09-03 01:25 UTCGHSA enrichment
  14. 2026-09-02 14:11 UTCEPSS rescore
  15. 2026-09-01 21:57 UTCEG score recompute
  16. 2026-09-01 21:57 UTCGHSA enrichment
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-08-31 19:35 UTCEG score recompute
  20. 2026-08-31 19:34 UTCGHSA enrichment
  21. 2026-08-30 19:17 UTCEPSS rescore
  22. 2026-08-30 10:58 UTCEG score recompute
  23. 2026-08-30 10:58 UTCGHSA enrichment
  24. 2026-08-30 01:22 UTCEPSS rescore
  25. 2026-08-29 08:34 UTCEG score recompute
  26. 2026-08-29 08:34 UTCGHSA enrichment
  27. 2026-08-28 21:41 UTCEPSS rescore
  28. 2026-08-27 23:17 UTCEG score recompute
  29. 2026-08-27 23:17 UTCGHSA enrichment
  30. 2026-08-27 14:25 UTCEPSS rescore
  31. 2026-08-26 20:53 UTCEG score recompute
  32. 2026-08-26 20:53 UTCGHSA enrichment
  33. 2026-08-26 14:46 UTCEPSS rescore
  34. 2026-08-25 18:10 UTCEG score recompute
  35. 2026-08-25 18:10 UTCGHSA enrichment
  36. 2026-08-25 13:48 UTCEPSS rescore
  37. 2026-08-24 15:42 UTCEG score recompute
  38. 2026-08-24 15:42 UTCGHSA enrichment
  39. 2026-08-23 13:11 UTCGHSA enrichment
  40. 2026-08-22 10:34 UTCEG score recompute
  41. 2026-08-22 10:34 UTCGHSA enrichment
  42. 2026-08-21 23:49 UTCEPSS rescore
  43. 2026-08-21 08:11 UTCEG score recompute
  44. 2026-08-21 08:11 UTCGHSA enrichment
  45. 2026-08-20 22:55 UTCEPSS rescore
  46. 2026-08-20 05:48 UTCEG score recompute
  47. 2026-08-20 05:48 UTCGHSA enrichment
  48. 2026-08-19 17:03 UTCEPSS rescore
  49. 2026-08-19 03:24 UTCEG score recompute
  50. 2026-08-19 03:24 UTCGHSA enrichment
  51. 2026-08-18 13:48 UTCEPSS rescore
  52. 2026-08-18 01:00 UTCEG score recompute
  53. 2026-08-18 01:00 UTCGHSA enrichment
  54. 2026-08-17 13:47 UTCEPSS rescore
  55. 2026-08-16 22:37 UTCEG score recompute
  56. 2026-08-16 22:37 UTCGHSA enrichment
  57. 2026-08-16 14:56 UTCEPSS rescore
  58. 2026-08-16 02:14 UTCEPSS rescore
  59. 2026-08-15 20:14 UTCEG score recompute
  60. 2026-08-15 20:14 UTCGHSA enrichment
  61. 2026-08-15 01:30 UTCEPSS rescore
  62. 2026-08-14 17:50 UTCEG score recompute
  63. 2026-08-14 17:50 UTCGHSA enrichment
  64. 2026-08-13 22:00 UTCEPSS rescore
  65. 2026-08-13 15:27 UTCEG score recompute
  66. 2026-08-13 15:27 UTCGHSA enrichment
  67. 2026-08-13 15:15 UTCEG score recompute
  68. 2026-08-13 15:15 UTCGHSA enrichment
  69. 2026-08-12 19:19 UTCEG score recompute
  70. 2026-08-12 18:56 UTCEG score recompute
  71. 2026-08-12 18:55 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-18676?
CVE-2026-18676 is a medium vulnerability published on August 12, 2026. The default kuma-cp configuration in Kong Mesh reveals the admin bootstrap token and signing keys to any webpage the operator visits while the control plane is reachable from their browser. Due to a CORS misconfiguration a cross-origin fetch() from a malicious page returns the admin JWT and signing…
When was CVE-2026-18676 disclosed?
CVE-2026-18676 was first published in the National Vulnerability Database on August 12, 2026, with the most recent update on August 31, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-18676 actively exploited?
CVE-2026-18676 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 85.8% of all scored CVEs.
What is the CVSS score of CVE-2026-18676?
CVE-2026-18676 has a CVSS v3 base score of 5.1 (NVD).
How do I remediate CVE-2026-18676?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-18676, 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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