{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-103435","assignerOrgId":"98a01053-8a31-4f6d-9aa9-252be161adc6","state":"PUBLISHED","assignerShortName":"Anthropic","dateReserved":"2026-09-30T15:35:18.777Z","datePublished":"2026-10-07T12:50:02.572Z","dateUpdated":"2026-10-07T14:39:13.225Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Anthropic","product":"@anthropic-ai/claude-code","versions":[{"version":"0","lessThan":"2.1.129","status":"affected","versionType":"semver"}]}],"problemTypes":[{"descriptions":[{"lang":"en","type":"CWE","cweId":"CWE-22","description":"CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')"}]},{"descriptions":[{"lang":"en","type":"CWE","cweId":"CWE-61","description":"CWE-61 UNIX Symbolic Link (Symlink) Following"}]},{"descriptions":[{"lang":"en","type":"CWE","cweId":"CWE-367","description":"CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition"}]}],"references":[{"url":"https://github.com/anthropics/claude-code/security/advisories/GHSA-5j29-h97v-84ch"}],"metrics":[{"cvssV4_0":{"version":"4.0","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","baseScore":7.7,"baseSeverity":"HIGH"}}],"title":"Arbitrary File Write via Write-Time Symlink Following (TOCTOU) in Claude Code","providerMetadata":{"orgId":"98a01053-8a31-4f6d-9aa9-252be161adc6","shortName":"Anthropic","dateUpdated":"2026-10-07T12:50:02.572Z"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-07T14:39:02.916533Z","id":"CVE-2026-103435","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-07T14:39:13.225Z"}}]}}