# CVE-2026-111764: A2A Java SDK missing task authorization in default configuration

Source: https://junglewise.ai/threats/cve-2026-111764-a2a-java-sdk-is-the-official-java-sdk-for-the-agent2agent-a2a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-20. Updated: 2026-10-20  
License: CC BY 4.0 with a link back

CVE-2026-111764 · Severity: high · CVSS 7.5 · Published 2026-10-20

The A2A Java SDK is the official library for Agent2Agent protocol communication. In default configurations prior to 1.3.0.Final, the task storage component does not perform authorization checks, allowing any caller who knows or guesses a task ID to retrieve sensitive task details including status, context, messages, and artifacts. Since the default transport endpoints lack authentication, this disclosure is reachable without credentials.

Technologies: [A2A Project A2A Java SDK](https://junglewise.ai/threats/technologies/a2a-java-sdk). Vendors: [A2A Project](https://junglewise.ai/threats/vendors/a2a-project), [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2026-111764 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111764 being exploited in the wild.

**How severe is CVE-2026-111764?** High severity, with a CVSS score of 7.5, published 20 October 2026.

**Which products and versions are affected?** A2A Project A2A Java SDK before 1.3.0.Final; org.a2aproject.sdk:a2a-java-sdk-server-common (Maven) < 1.3.0.Final, ECOSYSTEM:introduced=0,fixed=1.3.0.Final.

**Is there a fix for CVE-2026-111764?** Yes. org.a2aproject.sdk:a2a-java-sdk-server-common (Maven): upgrade to 1.3.0.Final or later. Until then: Set the configuration property a2a.authorization.required=false only to restore previous behavior for single-user deployments or testing; applications should provide a TaskAuthorizationProvider or ensure AuthorizationRequestHandlerDecorator is installed via CDI or explicit application setup. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-111764 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-111764?** Check whether you run A2A Project A2A Java SDK or org.a2aproject.sdk:a2a-java-sdk-server-common (Maven) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- org.a2aproject.sdk:a2a-java-sdk-server-common (Maven): upgrade to 1.3.0.Final or later

  ```sh
  # set org.a2aproject.sdk:a2a-java-sdk-server-common to 1.3.0.Final in your pom.xml or build.gradle
  ```


Set the configuration property a2a.authorization.required=false only to restore previous behavior for single-user deployments or testing; applications should provide a TaskAuthorizationProvider or ensure AuthorizationRequestHandlerDecorator is installed via CDI or explicit application setup.

## Technical details

InMemoryTaskStore performs no authorization on task reads when the no-argument constructor is used (authorizationProvider set to null). The vulnerability affects default store wiring, manually constructed DefaultRequestHandler instances, and integrations like Spring, as authorization is bypassed when no TaskAuthorizationProvider and AuthorizationRequestHandlerDecorator are properly configured. An attacker can call InMemoryTaskStore.get(taskId) over unprotected transport endpoints to enumerate and retrieve task data belonging to other callers in multi-caller deployments.

## Affected products

- A2A Project A2A Java SDK before 1.3.0.Final

## Identifiers

- CVE-2026-111764
- GHSA-qw47-mcm5-934w

## Timeline

- 2026-10-20: disclosed
- 2026-08-26: patched

## References

- [https://github.com/a2aproject/a2a-java/commit/efb4e985e99390c4fc1f78c0a187a4254c0a2553](https://github.com/a2aproject/a2a-java/commit/efb4e985e99390c4fc1f78c0a187a4254c0a2553)
- [https://github.com/a2aproject/a2a-java/pull/1095](https://github.com/a2aproject/a2a-java/pull/1095)

## Related threats

- [A2A Java SDK credential disclosure via HTTP redirect](https://junglewise.ai/threats/cve-2026-111765-a2a-java-sdk-is-the-official-java-sdk-for-the-agent2agent-a2a)
- [A2A Java SDK credential leakage via header injection and redirects](https://junglewise.ai/threats/cve-2026-111763-a2a-java-sdk-is-the-official-java-sdk-for-the-agent2agent-a2a)
- [A2A Java SDK server-common SSRF in push notifications](https://junglewise.ai/threats/cve-2026-111761-a2a-java-sdk-is-the-official-java-sdk-for-the-agent2agent-a2a)