{"version":"2.1.300","anchor":"bash-like-command-rejects-invisible-ufeff-u180e-characte","canonical_anchor":"bash-like-command-rejects-invisible-ufeff-u180e-characte","heading":"Commands containing certain invisible characters are blocked instead of run","tier":"notice","area":"Bash Tool","scope":"individual","heads_up":true,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.300\/e\/bash-like-command-rejects-invisible-ufeff-u180e-characte","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.300","markdown":"### Commands containing certain invisible characters are blocked instead of run\n\nA command containing the invisible characters U+FEFF or U+180E is now refused, with a note on how to write them safely\n\n**Unclear.** It is not clear which command tool runs this check, the Bash tool or the PowerShell tool, or whether the check is always on.\n\n**What**\n\nClaude Code now refuses to run a command that contains either of two invisible characters:\n\n- U+FEFF, the byte order mark, a hidden marker sometimes left at the start of text files\n\n- U+180E, the Mongolian vowel separator\n\nThe command is not run. The message says which character was found and explains how to write it safely if it is really wanted. The suggested form, `$([char]0xFEFF)`, is written for PowerShell, the Windows command shell.\n\n**Why**\n\nThese characters cannot be seen on screen, so a command containing one can do something other than what it appears to do. A command like that now fails with a clear explanation instead of running.\n\n- Area: Bash Tool\n- Tier: You'll notice\n- Useful: 1\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: yes"}