{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64846","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-07-20T18:31:39.290Z","datePublished":"2026-08-20T16:18:06.729Z","dateUpdated":"2026-08-20T19:32:22.878Z"},"containers":{"cna":{"title":"Nix: Arbitrary file truncation outside the sandbox with recursive-nix experimental feature","problemTypes":[{"descriptions":[{"cweId":"CWE-61","lang":"en","description":"CWE-61: UNIX Symbolic Link (Symlink) Following","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-367","lang":"en","description":"CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"NONE","baseScore":2.8,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/NixOS/nix/security/advisories/GHSA-6h4g-g5j9-fm5f","tags":["x_refsource_CONFIRM"],"url":"https://github.com/NixOS/nix/security/advisories/GHSA-6h4g-g5j9-fm5f"},{"name":"https://github.com/NixOS/nix/pull/15401","tags":["x_refsource_MISC"],"url":"https://github.com/NixOS/nix/pull/15401"},{"name":"https://github.com/NixOS/nix/commit/26679828f74ee6e82a4100904e6361f993ff5390","tags":["x_refsource_MISC"],"url":"https://github.com/NixOS/nix/commit/26679828f74ee6e82a4100904e6361f993ff5390"}],"affected":[{"vendor":"NixOS","product":"nix","versions":[{"version":"< 2.35.0","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-08-20T16:18:06.729Z"},"descriptions":[{"lang":"en","value":"Nix is a package manager for Linux and other Unix systems. Prior to 2.35.0, a malicious derivation executed with the recursive-nix experimental feature can exploit a time-of-check/time-of-use race involving final symlink handling in the LocalStore restore path. The race can cause writeFile to follow a substituted final symlink when opening a path with O_TRUNC instead of enforcing FinalSymlink::DontFollow, allowing the Nix process or nix-daemon to create or truncate an empty file outside the build sandbox with the daemon user's permissions. The primitive does not provide arbitrary-content writes and requires winning the race. This issue is fixed in version 2.35.0."}],"source":{"advisory":"GHSA-6h4g-g5j9-fm5f","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-20T19:32:14.918442Z","id":"CVE-2026-64846","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-08-20T19:32:22.878Z"}}]}}