CVE-2026-19202
Google LLC · published 2026-09-22
Source record Collected from the National Vulnerability Database (NVD)
Description
Description by Google Inc. via the CVE Program.
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.
Status at the source
- NVD status: Awaiting Analysis — NVD has not analysed this CVE.
Affected products, as the source lists them
| Vendor | Product | Versions |
|---|---|---|
| mcp-toolbox-sdk-python | 0 – 1.1.0 and earlier: affected |
DeSpy has not checked any unit, hardware revision or firmware. A product missing here is not a statement that it is unaffected.
Scores, as their sources published them
- CVSS 4.0: 9.1 CRITICAL — as published by Google Inc. (Secondary)
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - SSVC — CISA's assessment (SSVC 2.0.3, CISA Coordinator): Exploitation: none · Automatable: yes · Technical impact: total
DeSpy does not score records. These are the sources' own values.
Weaknesses
Sources
References the source lists
Source dates: published 2026-09-22, last changed 2026-09-23. DeSpy's copy of this version is dated 2026-09-28.
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