{"id":"DEBIAN-CVE-2026-49114","details":"In ONNX before 1.21.0, the 'save_external_data' function builds the external-data file path from the model's external_data location field and opens it for writing without 'O_NOFOLLOW/O_EXCL', after a non-atomic 'os.path.isfile()' check. A local attacker with write access to the directory where a victim serializes external data can deterministically pre-plant a symlink that is being followed, causing the victim's write to append to any file the victim can write, e.g. ~/.ssh/authorized_keys, cron files, or application configs. Fixed in 1.21.0.","modified":"2026-09-17T08:47:26.261613055Z","published":"2026-08-21T16:17:17.863Z","upstream":["CVE-2026-49114"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-49114"}],"affected":[{"package":{"name":"onnx","ecosystem":"Debian:12","purl":"pkg:deb/debian/onnx?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.12.0-2","1.13.1-1","1.13.1-2","1.13.1-3","1.14.1-1","1.14.1-2","1.14.1-2.1","1.14.1-2.1~exp1","1.16.1-1","1.16.2-1","1.17.0-1","1.17.0-2","1.17.0-3","1.19.1-1~exp1","1.20.0-1","1.20.0-1~exp1","1.20.0-3","1.20.0-4","1.20.0-5","1.20.0-6","1.21.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49114.json"}},{"package":{"name":"onnx","ecosystem":"Debian:13","purl":"pkg:deb/debian/onnx?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.17.0-3","1.19.1-1~exp1","1.20.0-1","1.20.0-1~exp1","1.20.0-3","1.20.0-4","1.20.0-5","1.20.0-6","1.21.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49114.json"}},{"package":{"name":"onnx","ecosystem":"Debian:14","purl":"pkg:deb/debian/onnx?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.17.0-3","1.19.1-1~exp1","1.20.0-1","1.20.0-1~exp1","1.20.0-3","1.20.0-4","1.20.0-5","1.20.0-6","1.21.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-49114.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"}]}