language
Kotlin: security advisories, deprecations and releases
The Kotlin programming language.
- Items, 90 days
- 8
- Critical
- 0
- Last critical
- none
- This week
- 4
What your digest would have held this week
4 items from the last 7 days. Zero sends only the ones that touch your stack.
Deprecations 1
- HIGH NEW THIS WEEK ACT BY 21 OCT 2026 Kotlin Blog · 30 Oct 2026
Kotlin compiler will require JDK 17 or newer starting Kotlin 2.5.20-Beta1
Minimum JDK version for running the Kotlin compiler is increasing. JDK 17+ becomes mandatory in Kotlin 2.5.20-Beta1 with warnings starting in 2.5.0-Beta1.
Releases 3
- MEDIUM NEW THIS WEEK Kotlin Blog · 30 Oct 2026
Kotlin 2.5.0-Beta2 released with name-based destructuring and Java 28 support
Kotlin 2.5.0-Beta2 introduces stable name-based destructuring, unused return value checker, Java 28 support, Swift export Beta, and incremental Kotlin/Native compilation by default on Apple targets.
- LOW NEW THIS WEEK Kotlin Blog · 30 Oct 2026
Kotlin 2.4.21 maintenance release available with bug fixes
Kotlin 2.4.21 is a maintenance release containing bug fixes for those who prefer a stable release over the 2.5.0 betas.
- INFO Kotlin Blog · 3 Oct 2026
Kotlin 2.5.0-Beta1 introduces experimental companion blocks and extensions
Kotlin 2.5.0-Beta1 adds companion blocks and companion extensions as experimental features. These replace some companion-object use cases, compile to static members on JVM, and work across Kotlin/Java/Multiplatform.
News and tools 4
- INFO NEW THIS WEEK Kotlin Blog · 30 Oct 2026
State of Kotlin 2026 report published
New report shows over half of Kotlin developers work on backend projects, 93% use AI coding tools, and 81% find AI-generated code mostly correct.
- INFO Spring Blog · 16 Oct 2026
A Bootiful Podcast: Can Java be more performant than Rust? Andrew Lombardi has the numbers
Podcast episode discusses a Kotlin port of a real application and benchmarks comparing JVM and Rust performance with AI assistance.
- INFO Kotlin Blog · 15 Oct 2026
Write a title that states topic, problem, and benefit
Good titles name the subject and the concrete outcome attendees will gain; avoid vague or joke-only headlines.
- MEDIUM Kotlin Blog · 14 Oct 2026
Legacy Kotlin Migration: Four Parallel Tracks Instead of a Rewrite
Refactor Java/C++ payment systems incrementally: optimize existing code, switch to acceptance tests, add fitness functions, then migrate adapters and domain models.
Only hear about Kotlin when it touches your stack
Tell Zero what you run. You get one email, and only on the days something above applies to you.