{"id":"DEBIAN-CVE-2026-64846","details":"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.","modified":"2026-09-19T22:47:42.543718920Z","published":"2026-08-20T17:19:16.813Z","upstream":["CVE-2026-64846"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-64846"}],"affected":[{"package":{"name":"nix","ecosystem":"Debian:12","purl":"pkg:deb/debian/nix?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.16.1+dfsg-1","2.16.1+dfsg-2","2.16.1+dfsg-3","2.17.1+dfsg-1","2.18.1+dfsg-1","2.22.1+dfsg-1","2.23.3+dfsg-1","2.23.3+dfsg-2","2.24.12+dfsg-1","2.24.8+dfsg-1","2.24.9+dfsg-1","2.24.9+dfsg-2","2.25.4+dfsg-1","2.26.3+dfsg-1","2.32.5+dfsg-1","2.32.5+dfsg-2","2.34.3+dfsg-1","2.34.6+dfsg-1","2.34.8+dfsg-1","2.8.0-1.1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64846.json"}},{"package":{"name":"nix","ecosystem":"Debian:13","purl":"pkg:deb/debian/nix?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.26.3+dfsg-1","2.32.5+dfsg-1","2.32.5+dfsg-2","2.34.3+dfsg-1","2.34.6+dfsg-1","2.34.8+dfsg-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64846.json"}},{"package":{"name":"nix","ecosystem":"Debian:14","purl":"pkg:deb/debian/nix?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.26.3+dfsg-1","2.32.5+dfsg-1","2.32.5+dfsg-2","2.34.3+dfsg-1","2.34.6+dfsg-1","2.34.8+dfsg-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-64846.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:L/A:N"}]}