PublicCVE

CVE-2026-21852

MEDIUM5.3JSON exportCreate alert

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.

CVSS breakdown

CVSS 4.0
Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
Passive
Confidentiality (Vulnerable System)
Low
Integrity (Vulnerable System)
Low
Availability (Vulnerable System)
Low
Confidentiality (Subsequent System)
None
Integrity (Subsequent System)
None
Availability (Subsequent System)
None

Affected products