Google Agent Development Kit for Java up to 1.12.9 ADK Web missing origin validation in websockets

Summaryinfo

A vulnerability classified as critical was found in Google Agent Development Kit for Java up to 1.12.9. This issue affects some unknown processing of the component ADK Web. Executing a manipulation can lead to missing origin validation in websockets. This vulnerability is tracked as CVE-2026-107858. The attack can be launched remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Google Agent Development Kit for Java up to 1.12.9. It has been declared as critical. This vulnerability affects an unknown function of the component ADK Web. The manipulation with an unknown input leads to a missing origin validation in websockets vulnerability. The CWE definition for the vulnerability is CWE-1385. The product uses a WebSocket, but it does not properly verify that the source of data or communication is valid. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-107858 since 10/09/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 10/23/2026).

Upgrading to version 1.13.0 eliminates this vulnerability.

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Productinfo

Type

• Programming Language Software

Vendor

• Google

Name

• Agent Development Kit for Java

Version

• 1.12.0
• 1.12.1
• 1.12.2
• 1.12.3
• 1.12.4
• 1.12.5
• 1.12.6
• 1.12.7
• 1.12.8
• 1.12.9

License

• free

Website

• Vendor: https://www.google.com/

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