Insufficiently protected credentials in Claude Code - CVE-2026-21852
Published: April 30, 2026
Vulnerability identifier: #VU128519
CSH Severity: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-21852
CWE-ID: CWE-522
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Claude Code
Claude Code
Software vendor:
Anthropic
Anthropic
Description
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to exposure of sensitive information in the project-load flow when processing a repository settings file before trust confirmation. A remote attacker can provide a malicious repository that sets ANTHROPIC_BASE_URL to an attacker-controlled endpoint to disclose sensitive information.
User interaction is required to start Claude Code in an attacker-controlled repository.
Remediation
Install security update from vendor's website.