Java OpenJDK April 2026 Patch & Security Update

Hello Java customers!

We are happy to announce the latest April 2026 patch & security update release for the Microsoft Build of OpenJDK. Check our release notes page for details on fixes and enhancements or download and install the binaries today. The source code of our builds are now available on GitHub for further inspection:

• OpenJDK 25.0.3 (Note: this LTS has a separate source code branch for Microsoft’s release of Windows AArch64 OpenJDK 25.0.3)
• OpenJDK 21.0.11
• OpenJDK 17.0.19
• OpenJDK 11.0.31

Microsoft Build of OpenJDK specific updates

OpenJDK 25

• Fixes for the following issues on Windows AArch64:
  • 8383541: Safefetch should return the error value when accessing pages protected with PAGE_GUARD on Windows AArch64
• Implemented JDK-8357445: Time-Based Heap Uncommit During Idle Periods
  • Added support for automatic uncommitting of unused G1 heap regions during idle periods to reduce memory footprint in containerized and cloud environments
  • Disable with -XX:+UnlockDiagnosticVMOptions -XX:-G1UseTimeBasedHeapSizing
  • Beneficial for:
    • Containerized applications with variable workloads
    • Cloud deployments where memory usage affects billing
    • Applications needing memory footprint optimization with no effect on GC pause times
• AOTCache update
  • jcmd AOT.end_training has been incorporated upstream
  • AOTCache MXBean is still included in the latest patch related to AOTCache
  • With the AOTCache MXBean, you can programmatically stop the recording of training data without stopping your application
  • It also allows an application to determine if the recording of training data is active and how long the recording ran for

OpenJDK 21

• Fixes for the following issues on Windows AArch64:
  • 8383541: Safefetch should return the error value when accessing pages protected with PAGE_GUARD on Windows AArch64

OpenJDK 17

• Fixes for the following issues on Windows AArch64:
  • 8383541: Safefetch should return the error value when accessing pages protected with PAGE_GUARD on Windows AArch64

OpenJDK 11

• No Microsoft-specific updates for this release.

Summary of Upstream Updates

OpenJDK Vulnerability Advisory April 2026

OpenJDK 25

• List of fixes
• For further details, please refer to Oracle’s page on JDK25 consolidated release notes.

OpenJDK 21

• List of fixes
• For further details, please refer to Oracle’s page on JDK21 consolidated release notes.

OpenJDK 17

• List of fixes
• For further details, please refer to Oracle’s page on JDK17 consolidated release notes.

OpenJDK 11

• List of fixes
• For further details, please refer to Oracle’s page on JDK11 consolidated release notes.

OpenJDK 8

We continue to provide support on Azure and internally at Microsoft for OpenJDK 8 binaries of Eclipse Temurin built by the Eclipse Adoptium project. To facilitate its usage, we ship container images of OpenJDK 8 on top of Azure Linux and Ubuntu. Refer to our documentation.

• Download the latest Temurin build of OpenJDK 8

Questions?

Contact [email protected].

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