Path Traversal in Onnx
CVE-2026-49114
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.
Vulnerability class: Path Traversal (Directory Traversal)
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H.
Affected products
Weakness classification (CWE)
References
- 9119a7d8-5eab-497f-8521-727c672e3725 (vendor-advisory, exploit)
- 9119a7d8-5eab-497f-8521-727c672e3725 (third-party-advisory)
- 9119a7d8-5eab-497f-8521-727c672e3725 (vdb-entry)
Frequently asked questions
- What is CVE-2026-49114?
- CVE-2026-49114 is a high-severity vulnerability in Onnx, classified under Path Traversal. CVSS score: 7.1/10. Published 2026-08-21.
- How severe is CVE-2026-49114?
- High severity. CVSS v3 base score is 7.1 out of 10.