---
id: "CVE-2026-116479"
kind: "vulnerability"
aliases: ["CVE-2026-116479"]
title: "a2a-java: JSON-RPC error handler leaks information through error messages"
severity: "medium"
cvss: 5.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["a2a", "java", "json-rpc", "package"]
not_affected_if: ["not-using-a2a-java", "version-1.3.0-or-later"]
published_at: "2026-10-26T20:17:55+00:00"
first_seen_at: "2026-10-26T20:50:17+00:00"
updated_at: "2026-10-26T20:51:51+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-116479", "first_seen_at": "2026-10-26T20:50:17+00:00"}]
---

# a2a-java: JSON-RPC error handler leaks information through error messages

The getMessage function in the JSON-RPC Error Handler of a2a-java up to 1.2.0.Final exposes information through error messages. A remote attacker can trigger the error path and read the leaked details.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the a2a-java version in your build file (Maven `io.github.a2aproject:a2a-java` or equivalent) and confirm whether it is `1.2.0.Final` or earlier.
- unknown for other checks; the sources do not say which request or input triggers the leak.

## Fix

- Upgrade a2a-java to `1.3.0.Final` or later, per the upstream patch bbee3369f3825d0fba2373d821f6dc6d4fc82ec0.

## Timeline

- 2026-10-26T20:50:17+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-116479

## From the sources

A flaw has been found in a2aproject a2a-java up to 1.2.0.Final. This impacts the function getMessage of the component JSON-RPC Error Handler. This manipulation causes information exposure through error message. The attack can be initiated remotely. Upgrading to version 1.3.0.Final will fix this issue. Patch name: bbee3369f3825d0fba2373d821f6dc6d4fc82ec0. Upgrading the affected component is advised.

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