Helm 4.2 lands; Helm 3.21 ships with an explicit end-of-life warning

Helm shipped v4.2.0 and v3.21.0 on May 14, 2026. The notable change isn’t in the changelog — it’s the warning at the top of the v3.21.0 notes that Helm v3 is approaching end-of-life and that operators should plan their migration to v4.

What’s in v4.2

The release continues to track Kubernetes upstream tightly: client libraries are bumped to v1.36, Go is bumped to 1.26, and controller-runtime to v0.24. The headline functional changes:

• A new mustToToml template function for charts that need TOML rendering without dropping back to raw strings.
• --dry-run=server now honours generateName: instead of erroring on names that the apiserver would assign.
• The build switches to goreleaser; binaries are now produced for loong64 (LoongArch).
• Multiple fixes for post-renderers — hooks no longer collide with templates, and YAML separator parsing and Windows line-ending handling are corrected.

The --hide-notes and --render-subchart-notes flags are deprecated.

What’s in v3.21

The v3 line is in maintenance: this release upgrades opentelemetry packages to pick up patched CVEs and corrects a chart-path bug. No new functional surface.

Why this matters now

Helm v4 has been GA since November 12, 2025, but most production clusters still distribute v3 charts. The explicit “approaching end-of-life” language in a release-notes header — rather than a separate deprecation announcement — is the planning trigger: vendors will start dropping v3-only charts, and chart authors will need to validate against v4’s stricter template engine.

Sources: Helm v4.2.0, Helm v3.21.0 — May 14, 2026