---
id: "CVE-2026-113706"
kind: "vulnerability"
aliases: ["CVE-2026-113706"]
title: "a2a-rs: historyLength argument leaks information in in-memory task store"
severity: "medium"
cvss: 5.1
epss: 0.0025
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["a2a", "package", "rust", "self-hosted"]
not_affected_if: ["not-using-a2a-rs"]
published_at: "2026-10-21T00:17:48+00:00"
first_seen_at: "2026-10-23T21:57:27+00:00"
updated_at: "2026-10-25T04:29:02+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-113706", "first_seen_at": "2026-10-23T21:57:27+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-113706", "first_seen_at": "2026-10-24T13:15:55+00:00"}]
---

# a2a-rs: historyLength argument leaks information in in-memory task store

In a2a-rs up to 0.4.3, the historyLength argument handled by the in-memory task store can be manipulated to disclose information. The sources describe the impact only as information disclosure reachable remotely.

_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 or below `0.4.3`
- Check whether the a2a-server crate uses the in-memory task store (a2a-server/src/task_store/inmemory.rs)

## Fix

- Upgrade a2a-rs past `0.4.3` to a release that includes patch `68f1b7e772ae5d6c9e581ac9b48bcddd10fe70eb`
- unknown: the sources do not name a fixed release version

## Timeline

- 2026-10-23T21:57:27+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-113706
- 2026-10-24T13:15:55+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-113706

## From the sources

A vulnerability was identified in a2aproject a2a-rs up to 0.4.3. Impacted is an unknown function of the file a2a-server/src/task_store/inmemory.rs. The manipulation of the argument historyLength leads to information disclosure. The attack is possible to be carried out remotely. The identifier of the patch is 68f1b7e772ae5d6c9e581ac9b48bcddd10fe70eb. To fix this issue, it is recommended to deploy a patch.

---

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