Description
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.
Published: 2026-09-22
Score: 9.1 Critical
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Tue, 22 Sep 2026 22:00:00 +0000

Type Values Removed Values Added
Description 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.
Title Token Cache Reuse in mcp-toolbox-sdk-python
Weaknesses CWE-524
References
Metrics cvssV4_0

{'score': 9.1, 'vector': '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'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: Google

Published:

Updated: 2026-09-22T21:48:26.539Z

Reserved: 2026-08-07T05:27:47.674Z

Link: CVE-2026-19202

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-22T22:17:11.707

Modified: 2026-09-22T22:17:11.707

Link: CVE-2026-19202

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-22T23:45:18Z

Weaknesses