CVE-2026-116478 in a2a-go
Summary
by MITRE • 10/26/2026
A vulnerability was detected in a2aproject a2a-go up to 2.4.0. This affects the function CreateExecutor of the file a2asrv/agentexec.go of the component Push Notification Handler. The manipulation results in information exposure through error message. It is possible to launch the attack remotely. Upgrading to version 2.5.0 mitigates this issue. The patch is identified as f4d588216b0c9520e94d571bab725c38ce23064c. It is recommended to upgrade the affected component.
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Analysis
by VulDB Data Team • 10/26/2026
The a2a-go library, specifically within versions up to 2.4.0 of the Push Notification Handler component, contains a vulnerability in the CreateExecutor function located in the file a2asrv/agentexec.go. This flaw allows for information exposure through error messages generated during execution. The issue arises when the system encounters an unexpected state or invalid input while initializing an executor instance. Instead of returning a generic or sanitized error code that obscures internal details, the application leaks sensitive contextual data directly to the caller via standard error output mechanisms.
This type of vulnerability is classified under CWE-209 as Information Exposure Through an Error Message and aligns with ATT&CK technique T1530 Data from Cloud Storage Object Misconfiguration if the exposed information pertains to internal configuration or state that could aid in further exploitation. The root cause typically involves insufficient input validation or improper exception handling where stack traces, database connection strings, file paths, or internal variable states are included in the final error response sent over the network. In a remote context, this means an attacker can interact with the service and observe these detailed responses to map out the application's architecture, identify specific libraries used, or locate other potential attack vectors such as path traversal or injection points that rely on knowing exact internal structures.
The operational impact of this vulnerability is significant because it facilitates reconnaissance for subsequent attacks. By analyzing the leaked error messages, a remote attacker can gain insights into the server environment, potentially leading to more severe compromises such as unauthorized access or service disruption. Since the attack vector is remote, no authentication or physical proximity is required to exploit this flaw, making it particularly dangerous in internet-facing deployments. The exposure of internal logic reduces the effort required for an adversary to craft targeted payloads against other components within the same system.
To mitigate this risk, organizations should immediately upgrade a2a-go to version 2.5.0 or later, where the issue has been resolved by implementing stricter error handling practices that sanitize output before transmission. The specific patch addressing this vulnerability is identified as commit f4d588216b0c9520e94d571bab725c38ce23064c in the project repository. In addition to upgrading, developers should review other parts of the codebase for similar patterns where error messages might leak sensitive information and implement centralized logging that captures detailed errors internally while returning generic messages externally. This defense-in-depth approach ensures that even if one component fails to sanitize output properly, the overall system remains resilient against information disclosure attacks.