Vulnerability · Published Oct 23, 2026 · Assigned by Google
CVE-2026-107858Cross-Site WebSocket Hijacking and Permissive CORS in Google Agent Development Kit (ADK) for Java Development Server
High 7.2
In plain English
A high-severity missing authentication in Agent Development Kit (ADK) for Java from Google. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 30% of all known vulnerabilities).
Official description
Missing Origin Validation in WebSockets (CWE-1385) and Permissive Cross-domain Policy with Untrusted Domains (CWE-942) in the development web server (ADK Web) in Google Agent Development Kit (ADK) for Java (com.google.adk:google-adk-dev versions 0.1.0 before 1.13.0 and com.google.adk:google-adk-maven-plugin versions 0.3.0 before 1.13.0) allow a remote attacker to control a locally running agent and read its data via a malicious web page visited by a developer while the server is running. The /run_live WebSocket endpoint accepts connections from any origin by default (hardcoded via setAllowedOrigins("*") in versions 0.1.0 through 1.5.0, and defaulting to * via adk.web.cors.origins in versions 1.6.0 through 1.12.0), and since version 0.4.0 the REST API returns Access-Control-Allow-Origin: * by default. Because the server has no authentication and requests originate from the developer's browser (so binding to localhost does not prevent exploitation), a cross-origin page can send messages to the agent (triggering registered tools), stream agent responses, and list, read, create, or delete sessions and artifacts. In versions 1.6.0 through 1.12.0, users can mitigate the issue by setting the adk.web.cors.origins property to an explicit allowlist of trusted origins (such as http://localhost:8000). The vulnerability is fixed in version 1.13.0, which enforces a same-origin default for CORS and the /run_live WebSocket endpoint, and rejects DNS-rebinding requests over loopback.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Agent Development Kit (ADK) for Java | 0.1.0 – before 1.13.0 | |
| Agent Development Kit (ADK) for Java | 0.3.0 – before 1.13.0 |
Weakness: CWE-1385, CWE-942, CWE-306 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:L/VA:L/SC:N/SI:N/SA:N
References
- https://github.com/google/adk-java/issues/1257 issue-tracking, exploit
- https://github.com/google/adk-java/releases/tag/v1.13.0 release-notes
- https://github.com/google/adk-java/commit/5667d382ab5078a0d6e8f7184713a6bab767e004 patch
- https://github.com/google/adk-java/commit/1ae5078072e13e101318e32833f1db323ef084e1 patch
- https://github.com/google/adk-java/pull/1222 mitigation, patch
- https://github.com/google/adk-java/commit/c2b087cbaf44f44d20dc946d8f2391506a2fce3d mitigation, patch
- https://github.com/google/adk-java/releases/tag/v1.6.0 release-notes