CVE-2026-49114
ONNX symlink-following and path-traversal arbitrary file write
CVSS Score
7.1
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-367 CWE-22 CWE-59 |
| Vendor | onnx |
| Product | onnx |
| Published | Aug 21, 2026 |
| Last Updated | Aug 21, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
Affected Versions
ONNX / ONNX
0 < 1.21.0
References
Credits
tsigouris007 kpatsakis