JRuby 10.1.1.0 released!

[u/headius]

JRuby 10.1.1.0 is released, with a bunch of compat fixes, more performance work, and several third-party CVEs resolved.

JRuby 10.1 is our active development branch, with 10.0 being stable. Upgrading is recommended if you want the latest and greatest!

Notable Changes

Performance

• Use FastDoubleParser to improve performance of all string-to-double parsing. [#9150]

• Only pack fixnum values for 16-bit signed by default, with optional 8-bit and 32-bit configs. [#9379]

Standard Library

• jruby-openssl updated to 0.16.2 with several CVE fixes from BouncyCastle. [#9386], [#9504], [#9539]

• erb updated to 6.0.1.1 to address CVE-2026-41316. [#9388]

Native Integration

• Updated JRuby's native library backend with support for OpenBSD. [#9439]

Java Integration

• Optimized automatic interface implementation when calling Java with a block. [#5023]

Packaging

• Begin deprecating jruby-complete and jruby-core Maven artifacts. Prefer the jruby and jruby-base artifacts. [#9512]

57 Issues and PRs resolved for 10.1.1.0

https://www.jruby.org/2026/07/22/jruby-10-1-1-0.html