{"id":"CVE-2026-21852","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-21852","summary":"Claude Code Leaks Data via Malicious Environment Configuration Before Trust Confirmation","details":"A vulnerability in Claude Code's project-load flow allowed malicious repositories to exfiltrate data including Anthropic API keys before users confirmed trust. If a user started Claude Code in an attacker-controller repository, and the repository included a settings file that set ANTHROPIC_BASE_URL to an attacker-controlled endpoint, Claude Code would issue API requests before showing the trust prompt, including potentially leaking the user's API keys.\n\nUsers on standard Claude Code auto-update have received this fix already. Users performing manual updates are advised to update to the latest version.","published":"2026-01-21T01:00:31Z","modified":"2026-02-03T03:11:19.470547Z","cvss":null,"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@anthropic-ai/claude-code","fixedVersion":"2.0.65"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/anthropics/claude-code/security/advisories/GHSA-jh7p-qr78-84p7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21852"},{"type":"PACKAGE","url":"https://github.com/anthropics/claude-code"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-02-03T03:11:19.470547Z"}}