---
id: "CVE-2026-113705"
kind: "vulnerability"
aliases: ["CVE-2026-113705"]
title: "a2a-rs: error handling in a2a-server leaks information to remote callers"
severity: "medium"
cvss: 6.9
epss: 0.00332
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["a2a", "package", "rust", "self-hosted"]
not_affected_if: ["no-network-exposure"]
published_at: "2026-10-20T23:17:10+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T03:40:17+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-113705", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-113705", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# a2a-rs: error handling in a2a-server leaks information to remote callers

Up to version 0.4.3 of the a2a-rs Rust library, the a2a-server error handling in error.rs can expose information through error messages. A remote attacker can trigger the flaw by manipulating requests, and may read internal details from the responses.

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

## How to check

- Check the a2a-rs version in Cargo.lock or Cargo.toml for `a2a-rs` at `0.4.3` or earlier
- Confirm whether `a2a-server` from that crate is deployed and reachable from the network

## Fix

- Apply the upstream patch referenced as commit `713b943af94ab2d521d483b841618b97a2e78a4d`
- Move to a newer a2a-rs release that includes this patch once one is published (version unknown from sources)

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-113705
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-113705

## From the sources

A vulnerability was determined in a2aproject a2a-rs up to 0.4.3. This issue affects some unknown processing of the file a2a-server/src/error.rs. Executing a manipulation can lead to information exposure through error message. The attack can be executed remotely. This patch is called 713b943af94ab2d521d483b841618b97a2e78a4d. A patch should be applied to remediate this issue.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_