Vulnerability · Published Nov 4, 2026 · Assigned by apache
CVE-2026-103582Apache ActiveMQ NMS OpenWire Client Library: Unbounded/Unvalidated Length Fields in Apache.NMS.OpenWire Unmarshalling (DoS)
Unrated
In plain English
A security flaw in Apache ActiveMQ NMS OpenWire Client Library from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:24.04:LTS | activemq | no fix listed | UBUNTU-CVE-2026-103582 |
| Ubuntu:26.04:LTS | activemq | no fix listed | UBUNTU-CVE-2026-103582 |
| Ubuntu:26.10 | activemq | no fix listed | UBUNTU-CVE-2026-103582 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache ActiveMQ NMS OpenWire Client Library | 0 – through 2.2.0 |
Weakness: CWE-789