# Claude Code 2.1.210: worktree isolation escape fixed, ultracode opt-in restricted to human input

> Fixes an isolation hole where `isolation: 'worktree'` subagents could run git-mutating commands against the main checkout, and stops the `ultracode` keyword from triggering on webhook payloads and relayed PR comments. Adds a startup warning for `Write(path)`/`NotebookEdit(path)`/`Glob(path)` permission rules.

| | |
|---|---|
| **Tool** | Claude Code |
| **Version** | 2.1.210 |
| **Kind** | release |
| **Published** | 2026-07-14 |
| **Observed** | 2026-08-11 |
| **Significance** | 3/5 |
| **Breaking** | no |
| **Categories** | fix, security, feature |

## What changed


- Fixed `isolation: 'worktree'` subagents mutating git in the main repo checkout instead of their own worktree
- Fixed the `ultracode` keyword opt-in firing on non-human input (webhook payloads, relayed PR comments)
- Hardened the Agent tool against indirect prompt injection via content a subagent read
- Startup warning for `Write(path)`, `NotebookEdit(path)`, `Glob(path)` permission rules — use `Edit(path)` or `Read(path)`
- Live elapsed-time counter on collapsed tool summary lines
- Fixed a hook callback timeout being reported to the model as a user rejection, which stalled unattended sessions
- Fixed Claude assuming a `cd` took effect after its command was backgrounded; the result now states the directory is unchanged
- Fixed plugin-provided MCP servers torn down on mid-session MCP re-sync
- Fixed plan approvals with no edits labeled "(edited by user)" and overwriting the plan file with a stale snapshot
- Fixed `claude agents --effort ultracode` being silently dropped, and `claude attach` "job not found" errors during session transitions
- Fixed killed background sessions leaving a permanent `git worktree lock`
- Fixed unmatched `$1`/`$2` placeholders in skills and commands being silently stripped
- Auto mode's permission classifier defaults to Sonnet 5 for external sessions, pinned for the session
- Memory writes leaving MEMORY.md over its read limit now error instead of truncating silently
- Fable temporarily marked unavailable in the advisor picker pending a server-side fix


## Sources

- [changelog_md](https://github.com/anthropics/claude-code/blob/main/CHANGELOG.md) — retrieved 2026-08-11

## Community

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and never blended._

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Canonical: https://changelogs.info/claude-code/2-1-210
Entity: https://changelogs.info/claude-code
Event ID: `evt_2026-07-14_claude-code_2-1-210`
Licence: event synthesis © changelogs.info, CC BY 4.0. Linked sources belong to their vendors.