Version: Wowza Streaming Engine™ 4.9.4+3 build 20250424142915 released April 29, 2025.
Java support: Wowza Streaming Engine 4.9.4 is compiled using Java 17 (OpenJDK Java SE JRE 17.0.12) but can be used with Java versions 17 or 21. For more details, see Java version information.
New features and functionality in Wowza Streaming Engine 4.9.4
Wowza Streaming Engine is a robust, customizable, and scalable media server software that powers reliable streaming of high-quality video and audio to any device, anywhere.
Support for SRT listener mode
With Wowza Streaming Engine 4.9.4, we've improved our SRT implementation to include listener mode.
SRT listener mode offers a simplified configuration. Multiple SRT streams can be pushed directly to Wowza Streaming Engine without the need to create separate .stream files for each incoming stream. The new listener workflow also supports port multiplexing, requiring only one SRT port for multiple inbound SRT connections. This change reduces efforts to manage firewall settings and to open numerous UDP ports when connecting SRT listener streams. For encryption and security, enhanced passphrase and stream ID features provide an efficient way to manage, identify, and route streams in a multi-stream or multi-tenant environment.
Setting up SRT listener mode requires a one-time configuration of Server.xml, VHost.xml, and Application.xml files. For more, see Ingest and publish an SRT stream with Wowza Streaming Engine.
Installation and update considerations for Wowza Streaming Engine 4.9.4
If you're updating to Wowza Streaming Engine 4.9.4 from a base installation of Wowza Streaming Engine 4.9.3 or earlier, see Updating to Wowza Streaming Engine 4.9.0 and later.
Note: Wowza Streaming Engine 4.8.28 and later doesn't include an updater or installer for macOS.
When using the Wowza Streaming Engine 4.9.4 installer to add a new instance of Wowza Streaming Engine on Windows, you may need to install additional dependencies to ingest SRT MediaCaster streams or use the generic SRT stream targets destination to publish an SRT stream. For more information, see our Ingest and publish an SRT stream guide.
For step-by-step instructions on how to install or update Wowza Streaming Engine, see the following articles:
- Install – Install and configure Wowza Streaming Engine
- Update – Update your Wowza Streaming Engine installation
Breaking changes in Wowza Streaming Engine 4.9.4
Java version information
Wowza Streaming Engine 4.9.0 - 4.9.4 is officially certified, thoroughly tested, and optimized to run seamlessly with the Java 21 JRE. You get the following Java features:
- Installer details – Wowza Streaming Engine 4.9.0 - 4.9.4 is compiled using Java 17 (OpenJDK Java SE JRE 17.0.12), but new installations include a JRE for Java 21 (OpenJDK Java SE JRE 21.0.3). You can roll back to Java 17 if needed. Older Java versions (16 and below) are no longer supported and cannot be used with Wowza Streaming Engine 4.9.0 and later.
- Updater details – When using the updater for Wowza Streaming Engine 4.9.0 - 4.9.4, we verify that the Java 21 Virtual Machine (JVM) is present before completing the upgrade. If Java 21 isn't detected on the machine, the update is canceled with a message containing recommended steps. If you need a new version of Java, the updater includes JRE 21 with instructions explaining how to copy it from the root of the installer to the Wowza Streaming Engine installation folder. When you're updating to Wowza Streaming Engine 4.9.0 - 4.9.4 from a base installation of Wowza Streaming Engine 4.8.28 or earlier, check these considerations.
- Supported Java versions – If you prefer, you can manually install a different Java version. We support Java versions 17 or 21 with Wowza Streaming Engine 4.9.0 - 4.9.4.
While we tested Wowza Streaming Engine 4.8.28 - 4.9.4 with the Java 21 Runtime Environment (JRE), we didn't recompile it using Java Development Kit (JDK) 21. If you build a custom module using Java 21, it may not work with Wowza Streaming Engine if your source code includes Java 21 features.
Note: New installations of Wowza Streaming Engine 4.8.28 and later deliver generational support for the Z Garbage Collector (ZGC). To use Java 21 with Generational ZGC on Windows, you must be running a 64-bit version of Windows 10 (version 1803 or later) or Windows Server 2019 or later. You also need a 64-bit JVM.
If your Wowza Streaming Engine workflow uses custom modules or plugins, we suggest testing them with Wowza Streaming Engine 4.8.28 - 4.9.4 in a non-production environment before updating your media server software. The following Java modules are included with the JRE and installer for the Wowza Streaming Engine 4.8.28 - 4.9.4:
- java.base
- java.datatransfer
- java.desktop
- java.instrument
- java.logging
- java.management
- java.management.rmi
- java.naming
- java.prefs
- java.rmi
- java.scripting
- java.scripting.jgss
- java.security.sasl
- java.sql
- java.transaction.xa
- java.xml
- jdk.crypto.cryptoki
- jdk.crypto.ec
- jdk.httpserver
- jdk.management
- jdk.management.agent
- jdk.naming.rmi
- jdk.unsupported
- jdk.xml.dom
- jdk.attach (available with Wowza Streaming Engine 4.8.28 and later)
- jdk.internal.jvmstat (available with Wowza Streaming Engine 4.8.28 and later)
- jdk.jcmd (available with Wowza Streaming Engine 4.8.28 and later)
- jdk.jfr (available with Wowza Streaming Engine 4.8.28 and later)
- java.net.http (available with Wowza Streaming Engine 4.8.28 and later)
If you have other dependencies, you must install a Java 17 JRE or JDK for Wowza Streaming Engine 4.9.0 - 4.9.4 that includes these dependencies. For more information, see Manually install and troubleshoot Java on Wowza Streaming Engine.
You can also check the Wowza Streaming Engine support for Java page to learn more about the different Java versions we support.
Detailed list of changes in Wowza Streaming Engine 4.9.4
These changes were made since the release of Wowza Streaming Engine 4.9.3:
- Updated the Wowza Streaming Engine SRT implementation to include listener mode.
- Fixed org.apache.tomcat.embed/tomcat-embed-core 10.1.34 CVE-2025-24813 security vulnerability.
- Fixed CVE-2025-22228 security vulnerability by upgrading to org.springframework.security/spring-security-crypto 6.3.8.
- Fixed an issue occurring when live streaming via RTMP input or from a VOD source, causing a missing last segment in HLS output during playback.
- Fixed an issue occurring when live streaming via RTMP input or from a VOD source, causing a missing last segment in HLS output when pushing Wowza Video stream targets without transcoding.
- Fixed an issue causing repeating first frames in transcoded streams when ingesting MPEG2 sources.
- Fixed an issue with the Wowza Streaming Engine Windows updater that was limiting live stream transcoding.
- Fixed an issue with Wowza Streaming Engine 4.9.0 and later related to sending live streams to the Akamai HD network for distributed delivery.
Known issues with Wowza Streaming Engine 4.9.4
For a detailed list of currently known issues, see Known issues with Wowza Streaming Engine.
