CVE-2026-90820A security vulnerability has been detected in a2aproject a2a-java 1.2.0. The impacted element is the function AuthorizationRequestHandlerDecorator.onListTasks of the file server-common/src/main/java/org/a2aproject/sdk/server/requesthandlers/AuthorizationRequestHandlerDecorator.java. Such manipulation leads to missing authorization. The attack can be launched remotely. Upgrading to version 1.3.0 is sufficient to resolve this issue. The name of the patch is e9a1abf9c90c02b16d17293afdc3cc2f555d63a6. The affected component should be upgraded.