Homebrew 6.0 locks down third-party taps and sandboxes Linux builds

Homebrew 6.0.0 ships with tap trust, its biggest security change in years. Because third-party taps can contain arbitrary unsandboxed Ruby that executes on a user’s machine, Homebrew now refuses to evaluate or run tap code until the tap is explicitly trusted — official taps remain trusted by default. The release also stops auto-tapping untrusted taps, pins allow/forbid/trust lists to remotes, and extends the model into brew bundle. Alongside this, the project disclosed and fixed three advisories: an HTTPS-to-HTTP redirect protection bypass in the POST download strategy, root code execution via Git hooks in the macOS .pkg postinstall, and an installer flaw where a user-controlled /var/tmp plist could hand Homebrew ownership to a local attacker.

Linux users gain a Bubblewrap-based sandbox for build, test, and postinstall phases, bringing parity with macOS, where those phases were already isolated. The release also makes the internal JSON API the default, bundling all metadata into a single download so brew update hits the network less and runs faster, and adds startup optimizations, parallelized bottle fetching, and a ~30% faster brew leaves.

Informed by a user survey, ‘ask’ mode becomes the default for developers, so install and upgrade operations show a dependency plan and confirmation prompt before changing anything. brew bundle gets parallel formula installs by default plus npm, krew, and Windows winget extensions. The release adds initial macOS 27 (Golden Gate) support and sets a sunset timeline for Intel Macs: bottles stop building in September 2026, with full removal of x86_64 support in September 2027.