CVE-2026-21852

The record

Claude Code is an agentic coding tool. Prior to version 2.0.65, vulnerability in Claude Code's project-load flow allowed malicious repositories to exfiltrate data including Anthropic API keys before users confirmed trust. An attacker-controlled repository could include a settings file that sets ANTHROPIC_BASE_URL to an attacker-controlled endpoint and when the repository was opened, Claude Code would read the configuration and immediately issue API requests before showing the trust prompt, potentially leaking the user's API keys. Users on standard Claude Code auto-update have received this fix already. Users performing manual updates are advised to update to version 2.0.65, which contains a patch, or to the latest version.

Affected packages

Related vulnerabilities

• GHSA-jh7p-qr78-84p7 Claude Code Leaks Data via Malicious Environment Configuration Before Trust Confirmation Same vulnerability
• CVE-2026-54316 Claude Code is an agentic coding tool. Also affects @anthropic-ai/claude-code
• GHSA-fg94-h982-f3mm Claude Code: Out-of-Band Data Exfiltration via Pre-Approved HuggingFace Domain in WebFetch Also affects @anthropic-ai/claude-code
• CVE-2026-40068 In versions 2.1.63 through 2.1.83 of Claude Code, the folder trust determination logic… Also affects @anthropic-ai/claude-code
• GHSA-q5hj-mxqh-vv77 Claude Code: Trust Dialog Bypass via Git Worktree Spoofing Allows Arbitrary Code Execution Also affects @anthropic-ai/claude-code
• GHSA-vp62-r36r-9xqp Claude Code: Sandbox Escape via Symlink Following Allows Arbitrary File Write Outside… Also affects @anthropic-ai/claude-code
• CVE-2026-39861 Claude Code is an agentic coding tool. Also affects @anthropic-ai/claude-code
• GHSA-5cwg-9f6j-9jvx Claude Code: Insecure System-Wide Configuration Loading Enables Local Privilege… Also affects @anthropic-ai/claude-code