Claude HUD through 0.0.12, patched in commit 234d9aa, constructs OSC 8 terminal hyperlink escape sequences using raw cwd and branchUrl values without stripping control characters or encoding embedded values, allowing attackers to inject arbitrary ANSI codes into terminal sessions. Attackers can embed ESC+backslash sequences in the current working directory or branch URL to execute malicious ANSI codes including text color changes, forged prompts, and OSC 52 clipboard writes, or trigger outbound HTTP requests to attacker-controlled remotes when hyperlinks are clicked.