Sandboxing

Claude Code's New Write Block Misses a printf Redirect

Claude Code 2.1.314 (30 Oct 2026) adds permissions.blockWritesOutsideWorkingDirectories. In 24 headless runs the Write and Edit tools refused every path outside the project, including through a symlink, in /tmp, and with Write(*) and Edit(*) allow rules that let the same write through when the setting was off. A printf redirect in Bash to the same folder went through, because the shell redirect check consults Edit rules and working directories, not this block. Side effects: settings.json in any .claude folder becomes a hard refusal, EnterWorktree and ExitWorktree disappear from the tool list, repository-supplied additionalDirectories don't count, 2.1.312 ignores the key silently. Auto-memory and the session's plan file still save. The settings reference has no entry yet.