---
id: CVE-2026-103582
title: >-
  Apache ActiveMQ NMS OpenWire Client Library: Unbounded/Unvalidated Length
  Fields in Apache.NMS.OpenWire Unmarshalling (DoS)
summary: >-
  Unbounded memory allocation and missing frame size validation in Apache NMS
  ActiveMQ (the .NET OpenWire client, package Apache.NMS.ActiveMQ) before 2.3.0.




  The OpenWire unmarshalling code trusted the frame size and the length and
  count…
severity: none
cwe:
  - CWE-789
vendor: Apache Software Foundation
product: Apache.NMS.ActiveMQ
affected:
  - Apache.NMS.ActiveMQ <= 2.2.0
published: '2026-11-04'
updated: '2026-11-04'
sourceUpdated: '2026-11-04T11:10:00.963Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-103582'
references:
  - url: 'https://lists.apache.org/thread/vgn9pnsc7g9dhcctt804kd50tvs0ndq0'
tags:
  - cve.org
ingestedAt: '2026-11-05T20:33:06.727Z'
---

## Overview

Unbounded memory allocation and missing frame size validation in Apache NMS ActiveMQ (the .NET OpenWire client, package Apache.NMS.ActiveMQ) before 2.3.0.



The OpenWire unmarshalling code trusted the frame size and the length and count fields read from the network. It did not enforce a maximum frame size, and it did not check that decoded lengths fit within the frame being read. A malicious or compromised broker, or an attacker able to intercept and modify an unencrypted connection, could send a crafted OpenWire frame with an oversized or negative length. This could cause the client to attempt very large memory allocations, leading to excessive memory consumption, an OutOfMemoryException or an uncaught exception, and a denial of service of the client application.



Users are recommended to upgrade to version 2.3.0, which enforces a configurable maximum frame size and validates lengths against the size of the frame being read.

## Affected

- `Apache.NMS.ActiveMQ <= 2.2.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.