Terraform 1.15.7

Overview

HashiCorp has released Terraform 1.15.7 on June 24, 2026. This is a patch release in the stable 1.15 series, focused on concurrency safety and submodule validation fixes. No new features or breaking changes — pure stability.

Bug Fixes

• Concurrency safety in configs.Parser and SourceBundleParser — Resolved a race condition (#38745) that could cause intermittent parse failures when multiple configurations were loaded concurrently. The fix adds proper mutex locking around shared parser state.
• Submodule variable validation during init — Fixed an issue where terraform init would fail to validate variable declarations inside child modules sourced from Git submodules, producing cryptic error messages. Variables are now correctly resolved and validated before the init phase completes.

Enhancements (from 1.15.x series)

• Test skip_cleanup attribute — Test authors can now specify skip_cleanup within test files and run blocks, telling terraform test not to clean up state files produced by those run blocks — useful for debugging failed tests.

Upgrade Notes

Terraform 1.15.7 is a drop-in replacement for any 1.15.x installation. No configuration changes or provider updates are required. Run terraform version after upgrading to verify.

Attribution

This release includes contributions from the HashiCorp engineering team and community reporters who identified the parser race condition. Full details are available in the official changelog.