{"id":"CVE-2026-46406","aliases":["GHSA-4vp2-6q8c-pvq2"],"url":"https://o3.security/vulnerability/CVE-2026-46406","summary":"Claude Code: Insecure Temporary File in /copy Command Enables Response Disclosure and Symlink-Based File Write","details":"The Claude Code `/copy` command wrote responses to a hardcoded, predictable path (`/tmp/claude/response.md`) without UID isolation, randomness, or symlink protection. The file was created world-readable (0644) in a world-traversable directory (0755), allowing any local user to read a privileged user's Claude response, which could contain secrets or credentials. Additionally, because the path was static and predictable, a local attacker could pre-create the directory and plant a symlink at the expected file path, causing the privileged process to follow the symlink and overwrite an attacker-chosen file with the response text. Exploiting this required a local unprivileged user on the same system and a privileged user to run the `/copy` command.\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.\n\nClaude Code thanks hackerone.com/c_h4ck_0 for reporting this issue.","published":"2026-06-29T14:03:14.683Z","modified":"2026-10-21T02:58:11.355449567Z","cvss":null,"epss":{"score":0.00154,"percentile":0.04878,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@anthropic-ai/claude-code","fixedVersion":"2.1.128"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46406.json"},{"type":"ADVISORY","url":"https://github.com/anthropics/claude-code/security/advisories/GHSA-4vp2-6q8c-pvq2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46406"},{"type":"PACKAGE","url":"https://github.com/anthropics/claude-code"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-21T02:58:11.355449567Z"}}