CVE-2026-19202

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 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
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.

A caching flaw in the toolbox-core package of the mcp-toolbox-sdk-python SDK causes the same Google ID token to be cached and reused across different audiences. If an application uses the SDK to authenticate to two or more different audiences within the same process, the module-level token cache fails to key its cached tokens by the requested audience. Consequently, a valid, unexpired token minted for a sensitive service (Service A) can be retrieved from the cache and sent to a secondary service (Service B). An attacker who operates, compromises, or monitors traffic to Service B can capture this token and replay it to impersonate the victim application against Service A.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
56(Track)
EG Risk 56/100SSVC: 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%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
14%
KEV
Not listed

Published

September 22, 2026

Last Modified

September 23, 2026

Advisory Details (1)

Auto-updated Sep 22, 2026
Patch available. Sources: github_pr.
github_pr Patch Available

fix(toolbox-core): cache Google ID tokens per audience to prevent cross-audience token reuse

Patch available: googleapis/mcp-toolbox-sdk-python toolbox-core-v1.2.0 (PR #675 merged 2026-06-05)

https://github.com/googleapis/mcp-toolbox-sdk-python/pull/675

Vendor Advisories for CVE-2026-19202(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 16× in last 7d / 16× 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. 2026-09-24 04:02 UTCGHSA enrichment
  2. 2026-09-24 00:02 UTCGHSA enrichment
  3. 2026-09-23 20:01 UTCGHSA enrichment
  4. 2026-09-23 19:20 UTCGHSA enrichment
  5. 2026-09-23 15:20 UTCEG score recompute
  6. 2026-09-23 15:20 UTCGHSA enrichment
  7. 2026-09-23 15:15 UTCEG score recompute
  8. 2026-09-23 15:15 UTCGHSA enrichment
  9. 2026-09-23 14:37 UTCEG score recompute
  10. 2026-09-23 14:37 UTCGHSA enrichment
  11. 2026-09-23 10:37 UTCGHSA enrichment
  12. 2026-09-23 06:34 UTCGHSA enrichment
  13. 2026-09-23 02:34 UTCGHSA enrichment
  14. 2026-09-22 22:34 UTCEG score recompute
  15. 2026-09-22 21:53 UTCEG score recompute
  16. 2026-09-22 21:52 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-19202?
CVE-2026-19202 is a critical vulnerability published on September 22, 2026. A caching flaw in the toolbox-core package of the mcp-toolbox-sdk-python SDK causes the same Google ID token to be cached and reused across different audiences. If an application uses the SDK to authenticate to two or more different audiences within the same process, the module-level token cache…
When was CVE-2026-19202 disclosed?
CVE-2026-19202 was first published in the National Vulnerability Database on September 22, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-19202 actively exploited?
CVE-2026-19202 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 86.1% of all scored CVEs.
What is the CVSS score of CVE-2026-19202?
CVE-2026-19202 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-19202?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-19202, 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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