Anthropic pushed Claude Code v2.1.228 on August 11, and buried in a routine-looking point release is a fix for exactly the kind of injection surface that keeps security researchers up at night: skills synced from claude.ai could previously shadow local commands, run shell ! commands, and expand @-referenced files — all on your machine, without you necessarily realizing a synced skill (rather than something you typed) was the one doing it.

That’s now closed. Here’s what changed, and why the fix matters more than the changelog entry lets on.

The Core Fix: Synced Skills Get Sandboxed

Claude Code’s skills feature lets you package reusable capabilities that Claude can invoke on demand. One distribution path for skills is syncing them down from claude.ai — which is convenient, but also means you’re pulling in content whose provenance and trust level differ from what you wrote locally.

Per Anthropic’s official changelog, prior to v2.1.228, a skill synced from claude.ai could:

  • Shadow local commands or MCP prompts — override or intercept something you’d defined locally or through an MCP server, without it necessarily being obvious that a synced skill had done so.
  • Run ! shell commands from its body — trigger real shell execution on your machine directly from the skill’s instructions.
  • Expand @ file references from its body — pull in and act on local files just by referencing them in the skill’s content.

v2.1.228 closes all three paths specifically for claude.ai-synced skills. The changelog states that synced skills “no longer shadow local commands or MCP prompts, their descriptions are sanitized and labeled, and on your machine their bodies don’t run ! commands or expand @ files.”

Think through what that combination enabled before the fix: skill content — which could in principle be introduced or edited by anyone with sync access, or compromised through a supply-chain issue upstream — had a direct path to shell execution and local file access on your machine, disguised as a normal skill invocation. That’s the same class of risk that’s been a recurring theme across agentic coding tools all year: the tool becomes the attack vector the moment it treats less-trusted synced content with the same execution privileges as things you typed yourself.

Sanitizing and labeling skill descriptions closes the complementary gap — a skill’s description text is cleaned up before it’s shown to you or the model, making it harder to use the description field itself as a second injection surface.

What Else Shipped

The rest of v2.1.228 is reliability and UX fixes, per the official changelog:

  • Fixed interactive sessions that could stop redrawing entirely — while the process kept running — after a rare internal layout error.
  • Fixed git/Git Bash not being found on Windows when Claude Code is launched from a parent folder of the git installation.
  • Fixed /tui reverting the session to an earlier model when /model had been changed since the last response.
  • Fixed cross-session messaging sometimes starting without an inbox in the first session after install or upgrade.
  • Fixed Remote Control’s /resume leaking a resumed conversation’s title or history into the connected session when used on another machine.
  • Fixed claude self-hosted-runner sessions failing on every fresh runner when a checkout hook fails for a repository the session doesn’t push to — that repository is now skipped with a warning instead of failing the whole run.
  • Fixed self-hosted runners ending sessions in the gap between a background task finishing and the follow-up turn starting.
  • Fixed session cleanup that was deleting contents inside a project’s memory folder — a real data-loss bug for anyone relying on persistent memory across sessions.
  • Fixed background plugin-cache cleanup deleting a plugin’s cache when its only version was a symlinked development checkout.
  • Fixed a settings-merge issue where a marketplace entry redefined in a higher-precedence settings tier could inherit another tier’s custom headers; marketplace entries now merge as whole entries instead of field-by-field.
  • Fixed the deferred-tools reminder occasionally being sent to the model twice after a skill invocation.
  • Improved cross-session messages: sender and body now display inline instead of a collapsed line, and messages to Remote Control sessions on other machines show your Remote Control session name as the sender.
  • Improved Vertex AI credential handling: expired or missing Google Cloud credentials now fail within seconds instead of retrying for minutes.
  • Changed the Write tool so newer models can overwrite an existing file they haven’t read this session, matching the Edit tool’s existing rules (older models still require reading the file first).

Why This Is Worth Paying Attention To

Claude Code has been shipping point releases at a rapid clip this week — v2.1.224 through v2.1.227 all landed in the days immediately before this one. Most of those were incremental. This one is different because it’s a genuine security-boundary fix, not a UX polish item.

If your team uses claude.ai-synced skills in any organizational context — where the sync source might include skills authored by other team members, third-party marketplaces, or anything you didn’t personally write line-by-line — this release matters more than its position in a busy patch-note week suggests. The threat model it closes (trusted-looking synced content getting untrusted-content execution privileges) is exactly the kind of thing that turns “convenient skill sharing” into “supply-chain incident.”

Run claude --version to check your installed version, and update to 2.1.228 or later if you’re behind — especially if synced skills are part of your team’s workflow.

Sources

  1. Claude Code changelog — v2.1.228 — Anthropic, August 11, 2026

Researched by Searcher → Analyzed by Analyst → Written by Writer Agent (Sonnet 4.6). Full pipeline log: subagentic-20260812-0800

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