CVE-2026-11717

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under NVD CVSS v3. EPSS exploit probability: 0.2%, top 93% 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
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

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

An authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox.

When verifying an unparsed opaque token via an OAuth 2.0 introspection endpoint (RFC 7662), the toolbox decodes the response into an introspectResp struct where the Active field is declared as a pointer to a boolean (*bool). The code only explicitly rejects a token if the response contains a populated active field set to false (if introspectResp.Active != nil && !*introspectResp.Active). If an introspection endpoint responds with a payload that completely omits the mandatory active key, the internal variable remains nil, causing the conditional check to short-circuit. As a result, Toolbox accepts authorization tokens missing the "active" field, granting access to protected tools and underlying data sources.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
46(Track)
EG Risk 46/100SSVC: 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
Severity91% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

June 18, 2026

Last Modified

August 17, 2026

Advisory Details (1)

Auto-updated Aug 1, 2026
Patch available. Sources: github_pr.
github_pr Patch Available

fix(auth): separate Google and Generic MCP OAuth verification

Patch available: googleapis/mcp-toolbox v1.4.0 (PR #3341 merged 2026-06-04)

https://github.com/googleapis/mcp-toolbox/pull/3341

Vendor Advisories for CVE-2026-11717(1)

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

Affected Packages

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFixed inDependents
github.com/googleapis/mcp-toolbox—1.4.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 56× 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 104 total refreshes for this CVE.

  1. 2026-08-24 15:05 UTCEG score recompute
  2. 2026-08-23 01:12 UTCEG score recompute
  3. 2026-08-23 00:19 UTCEPSS rescore
  4. 2026-08-22 01:00 UTCEG score recompute
  5. 2026-08-21 23:48 UTCEPSS rescore
  6. 2026-08-20 23:48 UTCEG score recompute
  7. 2026-08-20 22:55 UTCEPSS rescore
  8. 2026-08-20 08:09 UTCEG score recompute
  9. 2026-08-19 17:03 UTCEPSS rescore
  10. 2026-08-19 07:44 UTCEG score recompute
  11. 2026-08-18 13:48 UTCEPSS rescore
  12. 2026-08-17 16:28 UTCEG score recompute▼ 0.20
  13. 2026-08-17 16:22 UTCNVD updateCVSS v3 → 9.1
  14. 2026-08-16 15:28 UTCEG score recompute
  15. 2026-08-16 14:56 UTCEPSS rescore
  16. 2026-08-16 04:30 UTCEG score recompute
  17. 2026-08-16 02:14 UTCEPSS rescore
  18. 2026-08-15 03:57 UTCEG score recompute
  19. 2026-08-15 01:30 UTCEPSS rescore
  20. 2026-08-13 22:41 UTCEG score recompute
  21. 2026-08-13 22:00 UTCEPSS rescore
  22. 2026-08-12 14:51 UTCEG score recompute
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  24. 2026-08-11 16:54 UTCEG score recompute
  25. 2026-08-11 13:42 UTCEPSS rescore
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  1. 2026-08-11 02:18 UTCEG score recompute
  2. 2026-08-10 23:59 UTCEPSS rescore
  3. 2026-08-09 17:17 UTCEG score recompute
  4. 2026-08-09 13:46 UTCEPSS rescore
  5. 2026-08-08 19:22 UTCEG score recompute
  6. 2026-08-08 16:37 UTCEPSS rescore
  7. 2026-08-07 17:45 UTCEG score recompute
  8. 2026-08-06 16:05 UTCEG score recompute
  9. 2026-08-06 13:46 UTCEPSS rescore
  10. 2026-08-05 21:46 UTCEG score recompute
  11. 2026-08-05 19:17 UTCEPSS rescore
  12. 2026-08-04 15:23 UTCEG score recompute
  13. 2026-08-04 15:09 UTCEPSS rescore
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  16. 2026-08-03 10:35 UTCEPSS rescore
  17. 2026-08-02 03:11 UTCEG score recompute
  18. 2026-08-02 02:26 UTCEPSS rescore
  19. 2026-08-01 05:10 UTCEG score recompute
  20. 2026-08-01 04:15 UTCEPSS rescore
  21. 2026-07-30 22:28 UTCEG score recompute
  22. 2026-07-30 16:27 UTCEPSS rescore
  23. 2026-07-30 03:08 UTCEG score recompute
  24. 2026-07-30 01:30 UTCEPSS rescore
  25. 2026-07-29 01:46 UTCEG score recompute
  26. 2026-07-28 15:36 UTCEPSS rescore
  27. 2026-07-27 18:07 UTCEG score recompute
  28. 2026-07-27 14:13 UTCEPSS rescore
  29. 2026-07-26 17:42 UTCEG score recompute
  30. 2026-07-26 14:54 UTCEPSS rescore
  31. 2026-07-26 14:54 UTCEPSS rescore
  32. 2026-07-25 14:17 UTCEPSS rescore
  33. 2026-07-24 14:17 UTCEPSS rescore
  34. 2026-07-23 14:18 UTCEPSS rescore
  35. 2026-07-23 03:04 UTCEG score recompute
  36. 2026-07-22 14:08 UTCEPSS rescore
  37. 2026-07-21 15:24 UTCEPSS rescore
  38. 2026-07-20 17:08 UTCEPSS rescore
  39. 2026-07-19 14:30 UTCEPSS rescore
  40. 2026-07-19 02:28 UTCEPSS rescore
  41. 2026-07-18 10:04 UTCEPSS rescore
  42. 2026-07-16 17:02 UTCEPSS rescore
  43. 2026-07-15 16:57 UTCEPSS rescore
  44. 2026-07-15 02:00 UTCEPSS rescore
  45. 2026-07-13 22:30 UTCEPSS rescore
  46. 2026-07-13 06:12 UTCEPSS rescore
  47. 2026-07-12 05:46 UTCEPSS rescore
  48. 2026-07-11 08:27 UTCEPSS rescore
  49. 2026-07-09 19:10 UTCEPSS rescore
  50. 2026-07-08 15:15 UTCEPSS rescore
  51. 2026-07-08 15:15 UTCEPSS rescore
  52. 2026-07-07 13:46 UTCEPSS rescore
  53. 2026-07-06 16:27 UTCEPSS rescore
  54. 2026-07-06 02:23 UTCEPSS rescore
  55. 2026-07-05 02:30 UTCEPSS rescore
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  57. 2026-07-04 06:31 UTCEPSS rescore
  58. 2026-07-01 15:06 UTCEPSS rescore
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  60. 2026-06-30 23:22 UTCEPSS rescore
  61. 2026-06-29 14:06 UTCEPSS rescore
  62. 2026-06-28 14:07 UTCEPSS rescore
  63. 2026-06-28 04:56 UTCEPSS rescore
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  65. 2026-06-27 03:08 UTCEPSS rescore
  66. 2026-06-25 13:49 UTCEPSS rescore
  67. 2026-06-24 14:05 UTCEPSS rescore
  68. 2026-06-23 21:32 UTCEPSS rescore
  69. 2026-06-22 21:40 UTCEG score recompute▲ 9.30
  70. 2026-06-22 21:36 UTCNVD updateCVSS v3 → 9.3 · CVSS v4 → 9.3
  71. 2026-06-22 14:25 UTCEPSS rescore
  72. 2026-06-22 14:25 UTCEPSS rescore
  73. 2026-06-21 14:56 UTCEPSS rescore
  74. 2026-06-21 14:56 UTCEPSS rescore
  75. 2026-06-21 01:59 UTCEPSS rescore

Frequently asked(5)

What is CVE-2026-11717?
CVE-2026-11717 is a critical vulnerability published on June 18, 2026. An authentication bypass vulnerability exists in the generic opaque token validation path (validateOpaqueToken) of googleapis/mcp-toolbox. When verifying an unparsed opaque token via an OAuth 2.0 introspection endpoint (RFC 7662), the toolbox decodes the response into an introspectResp struct where…
When was CVE-2026-11717 disclosed?
CVE-2026-11717 was first published in the National Vulnerability Database on June 18, 2026, with the most recent update on August 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-11717 actively exploited?
CVE-2026-11717 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 92.8% of all scored CVEs.
What is the CVSS score of CVE-2026-11717?
CVE-2026-11717 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-11717?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-11717, 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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