Vulnerability · Published Apr 1, 2026 · Assigned by GitHub_M
CVE-2026-34446ONNX: Arbitrary File Read via ExternalData Hardlink Bypass in ONNX load
Medium 4.7
In plain English
A medium-severity path traversal in onnx from onnx. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 8% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to version 1.21.0, there is an issue in onnx.load, the code checks for symlinks to prevent path traversal, but completely misses hardlinks because a hardlink looks exactly like a regular file on the filesystem. This issue has been patched in version 1.21.0.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | onnx | no fix listed | DEBIAN-CVE-2026-34446 |
| Debian:13 | onnx | no fix listed | DEBIAN-CVE-2026-34446 |
| Debian:14 | onnx | no fix listed | DEBIAN-CVE-2026-34446 |
| PyPI | onnx | 1.21.0 | GHSA-cmw6-hcpp-c6jp |
| PyPI | onnx | 1.21.0 | PYSEC-2026-2241 |
| Ubuntu:22.04:LTS | onnx | no fix listed | UBUNTU-CVE-2026-34446 |
| Ubuntu:25.10 | onnx | no fix listed | UBUNTU-CVE-2026-34446 |
| Ubuntu:26.04:LTS | onnx | no fix listed | UBUNTU-CVE-2026-34446 |
| Ubuntu:26.10 | onnx | no fix listed | UBUNTU-CVE-2026-34446 |
Affected products (as reported)
Weakness: CWE-22, CWE-61 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
References
- https://github.com/onnx/onnx/security/advisories/GHSA-cmw6-hcpp-c6jp x_refsource_CONFIRM
- https://github.com/onnx/onnx/commit/4755f8053928dce18a61db8fec71b69c74f786cb x_refsource_MISC