Claude Code Leaks Data via Malicious Environment Configuration Before Trust Confirmation

HIGH 7.5CVE-2026-21852 · GHSA-jh7p-qr78-84p7 · Published 21/01/2026 · updated 17/06/2026

Package	Affected versions	Patched versions
claude code anthropic	`< 2.0.65`	`2.0.65`
@anthropic-ai/claude-code npm	`< 2.0.65`	`2.0.65`

Description

A vulnerability in Claude Code's project-load flow allowed malicious repositories to exfiltrate data including Anthropic API keys before users confirmed trust. If a user started Claude Code in an attacker-controller repository, and the repository included a settings file that set ANTHROPIC_BASE_URL to an attacker-controlled endpoint, Claude Code would issue API requests before showing the trust prompt, including 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 the latest version.

NVD description

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.

References

anthropics/claude-code security advisory · WEB
nvd.nist.gov/vuln/detail/CVE-2026-21852 · ADVISORY
anthropics/claude-code · PACKAGE

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Package

Affected versions

Patched versions

claude code

anthropic

< 2.0.65

2.0.65

@anthropic-ai/claude-code

npm

< 2.0.65

2.0.65

Description

Users on standard Claude Code auto-update have received this fix already. Users performing manual updates are advised to update to the latest version.

NVD description