[BUG] Interactive TUI frozen + 90%+ CPU on Linux via SSH — input never accepted, claude -p works fine

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Environment

Claude Code version: 2.1.31
Node.js: v22.22.0 (also reproduced on v22.21.1)
OS: AlmaLinux (CentOS/RHEL-based), x86_64
Connection: SSH from Windows to Linux server
Terminal: Tested with VS Code Remote SSH, SolarPutty, and Windows Terminal native ssh — same result on all three
TERM: xterm-256color
LANG: nl_NL.utf8
Shell: bash

Bug Description
The interactive TUI renders the welcome screen correctly but never accepts keyboard input. The Claude process immediately spins to 89–98% CPU on a single core. In some cases the TUI sits frozen with no keystrokes registering; in other cases it automatically submits an empty/undefined prompt, receives a "Hi! How can I help you today?" response, and exits on its own.
This was working correctly 2 days prior on the same server with the same setup. No known configuration changes were made.

What Should Happen?

Expected Behavior
The input field should accept keyboard input and allow interactive conversation.
Actual Behavior
Two observed behaviors (varies between attempts):

Frozen input: Welcome screen shows, cursor visible, but no keystrokes register. Process uses ~90% CPU.
Auto-submit and exit: Claude immediately submits an empty prompt (query: undefined in debug log), gets a response, and exits back to shell.

Error Messages/Logs

What Works

claude --version → responds correctly
claude -p "test" → works fine, returns a response
cat and other interactive terminal programs work normally in the same SSH session
Authentication and API communication work (confirmed via debug logs)

Debug Log Evidence
The debug log (~/.claude/debug/latest) shows Claude submitting a prompt without waiting for user input:
UserPromptSubmit with query: undefined
...
Stream started - received first chunk
...
Stop with query: undefined
SessionEnd with query: other

Steps to Reproduce

Steps to Reproduce

SSH into a Linux server (AlmaLinux) from any SSH client
Run claude (from any directory)
Welcome screen renders, input field appears
Attempt to type — nothing happens, or Claude auto-submits an empty prompt and exits

Claude Model

None

Is this a regression?

I don't know

Last Working Version

Claude Code version: 2.1.31

Claude Code Version

Claude Code version: 2.1.31

Platform

Other

Operating System

Other Linux

Terminal/Shell

VS Code integrated terminal

Additional Information

Troubleshooting Already Attempted

Three different SSH clients (VS Code Remote SSH, SolarPutty, Windows Terminal ssh)
TERM=xterm-256color explicitly set
stty sane before launching
Launching from home dir and from project directories
Clean environment with env -i
Fresh Node.js install (v22.22.0) + fresh npm install -g @anthropic-ai/claude-code
Killed all zombie Claude processes between attempts
No .inputrc, no BASH_ENV, no Claude/Anthropic environment variables set
No NFS mounts — local filesystem, 12 GB RAM available, server not under load

Related Issues

#7171 — Same symptoms on Windows (frozen interactive mode, -p works)
#9929 — Same symptoms on Windows 11 (frozen, raw mode issue)
#11339 — 100% CPU in interactive mode on macOS
#18532 — 100% CPU freeze, infinite loop on macOS
#17787 — TUI input broken due to cursor position response leak

This appears to be the same underlying TUI/Ink input handling bug, but on Linux via SSH rather than native Windows or macOS.