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25.08.501.0

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25.08.501.0

Release Notes PDF

Release date: June 18, 2026

This release is based on the Azul Zing Build of OpenJDK (Zing) 25.08.500.0 and corresponds to the following OpenJDK versions:

Major Version OpenJDK Version

8

1.8.0_491-b3

11

11.0.30.0.101+1-LTS

17

17.0.18.0.101+1-LTS

21

21.0.10.0.101+1-LTS

What’s New

  • Zing 26.02.101.0 includes the Metaspace MemoryPool MXBean, for OpenJDK compatibility. This MXBean initializes a memory manager and dummy memory pool. However, since Zing tracks metadata in the Java Heap, included in the existing Zing Heap MXBean, it always reports 0 usage. The Metaspace MemoryPool MXBean is disabled by default and can be enabled using the command line option -XX:+EnableMetaspacePoolMXBean.

  • ReadyNow first-call event logging has been improved to use a synchronous code path. This eliminates rare JVM crashes caused by the previous asynchronous code path and provides consistent latency for ReadyNow logging.

Known Issues

  • There are no new issues to report in this release.

Resolved Issues

Issue ID Description

ZVM-38766

Fatal JVM crash due to timeout when reading class files under heavy memory pressure.

ZVM-38563
ZVM-38564

Unexpected heap size error caused by improper low memory detection and heap size calculation.

ZVM-38472

Incorrectly initialized superclass lists lead to miscompilation.

ZVM-38424

Ampere One ARM64 systems crash when running Falcon-compiled code.

ZVM-37982

Zing specific jstat options, e.g. jstat -gpgc, return invalid.

ZVM-36940

Container memory data missing from GC logs on systems using cgroup v1.

ZVM-36823

Some cryptographic operations run slower with the Unified Compiler enabled, causing significant performance degradation.

ZVM-34528

Specially constructed code can cause compiler to stack overflow and crash.