- Medium 5.3
CVE-2026-21852
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 fi…
Scores
The facts
- Published
- 21 January 2026
- Last changed
- 17 June 2026
- NVD status
- Analyzed
- Severity
- Medium, CVSS 5.3 out of 10 (version 4.0)
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R… - Weakness
- Affects
- anthropic claude code
- Known exploited
- Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
- EPSS
- 27.5% chance of exploitation activity in the next 30 days (percentile 98).
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