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HIGH

CVE-2026-21852

CVSS v3

7.5

HIGH

EPSS Score

27.9 %

exploit probability, as of 2026-09-25

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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, poten

Technical details

Published
2026-01-21
Last Modified
2026-02-02

Frequently asked questions

What is 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, poten

Is CVE-2026-21852 actively exploited?

Active exploitation of CVE-2026-21852 has not been confirmed. Its EPSS score was 27.9% on 2026-09-25, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-21852?

CVE-2026-21852 has a CVSS v3 base score of 7.5 (HIGH severity).

Is CVE-2026-21852 affecting your environment?

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