{"id":"CVE-2026-103435","published":"2026-10-07T13:17:16.690","lastModified":"2026-10-07T15:16:57.037","description":"Claude Code validated that a target file path resided within the project working directory at permission-check time, but re-resolved the path at write time without repeating that validation. This time-of-check to time-of-use (TOCTOU) gap allowed an attacker who could write to the workspace to atomically replace a project file with a symlink, causing Claude Code to follow the symlink and write its output to an arbitrary file outside the project sandbox. Exploitation required the ability to win a race condition against the write operation and write access to the shared workspace, enabling a lower-privileged attacker to redirect benign edits to sensitive files (e.g., shell configuration) in a higher-privileged session.\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\nThank you to hackerone.com/c_h4ck_0 for reporting this issue.","cvssScore":null,"cvssSeverity":null,"cvssVector":null,"cwes":["CWE-22","CWE-61","CWE-367"],"vendors":[],"products":[],"references":[{"url":"https://github.com/anthropics/claude-code/security/advisories/GHSA-5j29-h97v-84ch","tags":[]}],"exploitRefs":[{"url":"https://github.com/anthropics/claude-code/security/advisories/GHSA-5j29-h97v-84ch","tags":[]}],"hasPoc":true,"ai":null}