CVE 5.3 MEDIUM

Claude Code Leaks Data via Malicious Environment Configuration Before Trust Confirmation_CVE-2026-21852

5.3 / 10
MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N

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.

Basic Information

ID CVE-2026-21852
Source GitHub_M
Published Jan 21, 2026 at 20:42
Modified Jan 21, 2026 at 21:34

Affected Product

Vendor anthropics
Product claude-code
Version < 2.0.65
Affected Versions anthropics claude-code < 2.0.65

CWE Classification

References

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