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 13, 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—2.7.25—
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 19× in last 7d / 27× 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. 2026-08-20 22:55 UTCEPSS rescore
  2. 2026-08-20 05:48 UTCEG score recompute
  3. 2026-08-20 05:48 UTCGHSA enrichment
  4. 2026-08-19 17:03 UTCEPSS rescore
  5. 2026-08-19 03:24 UTCEG score recompute
  6. 2026-08-19 03:24 UTCGHSA enrichment
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-18 01:00 UTCEG score recompute
  9. 2026-08-18 01:00 UTCGHSA enrichment
  10. 2026-08-17 13:47 UTCEPSS rescore
  11. 2026-08-16 22:37 UTCEG score recompute
  12. 2026-08-16 22:37 UTCGHSA enrichment
  13. 2026-08-16 14:56 UTCEPSS rescore
  14. 2026-08-16 02:14 UTCEPSS rescore
  15. 2026-08-15 20:14 UTCEG score recompute
  16. 2026-08-15 20:14 UTCGHSA enrichment
  17. 2026-08-15 01:30 UTCEPSS rescore
  18. 2026-08-14 17:50 UTCEG score recompute
  19. 2026-08-14 17:50 UTCGHSA enrichment
  20. 2026-08-13 22:00 UTCEPSS rescore
  21. 2026-08-13 15:27 UTCEG score recompute
  22. 2026-08-13 15:27 UTCGHSA enrichment
  23. 2026-08-13 15:15 UTCEG score recompute
  24. 2026-08-13 15:15 UTCGHSA enrichment
  25. 2026-08-12 19:19 UTCEG score recompute
Show 2 more
  1. 2026-08-12 18:56 UTCEG score recompute
  2. 2026-08-12 18:55 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

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 13, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-18676

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