Puppet Core 8.20.0 Is Now Available

[Puppet Product Updates]

Today, we are announcing the release of Puppet Core 8.20.0. 

This release extends platform support, strengthens security across core dependencies, and improves the reliability of day-to-day agent operations. 

Why Upgrade 

Expand platform coverage 

Ubuntu 26.04 ARM is now a supported agent platform, allowing you to bring newly adopted infrastructure under Puppet management without delay. 

Maintain a secure and supported environment 

This release includes targeted updates to core dependencies — including OpenSSL, net-imap, and concurrent-ruby — addressing known vulnerabilities and helping reduce exposure across your managed estate. 

Improve day-to-day operational reliability 

Resolved issues in sensitive data handling, input validation, macOS service management, and Windows task execution help ensure more consistent and predictable agent behaviour across your infrastructure. 

 

What's New in Puppet Core 8.20.0 

Expanded platform support 

Ubuntu 26.04 ARM is now a supported Puppet agent platform, extending coverage to ARM-based Ubuntu 26.04 deployments. 

Security and dependency updates 

OpenSSL has been updated to version 3.0.21, addressing multiple CVEs. The bundled net-imap and concurrent-ruby libraries have also been updated to address known vulnerabilities. The Puppet team has additionally evaluated a set of curl CVEs and confirmed that Puppet Core is not impacted by any of them. 

More reliable handling of sensitive data 

Puppet Core now supports sensitive values in transactionstore.yaml during deferred execution. Previously, sensitive data written to this file could cause subsequent Puppet runs to fail — this is now resolved. 

 

More accurate input validation 
A correction to regex end-of-string matching ensures that environment and certificate names are validated more accurately, preventing invalid inputs from passing undetected. 

 

Improved macOS service management 

A race condition that caused service management to fail on macOS when the launchd overrides plist file was briefly truncated during writes has been resolved. Plist files are now written atomically, improving reliability on macOS 26 and other supported macOS versions. 

 

More reliable task execution on Windows 

A file-rename race condition in PXP agent that could cause task metadata write errors under concurrent or high-frequency execution on Windows has been resolved, improving task reliability. 

 

Next Steps 

• Upgrade to Puppet Core 8.20.0 to benefit from expanded platform support, security updates, and reliability improvements. 
• For full technical details, review the Puppet Core 8.20.0 release notes. 
• If you have questions or need assistance, contact support through the support portal. 

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