Home/CVE/Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to version 1.21.0,
CVE

CVE-2026-34446

Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to version 1.21.0,

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.

MEDIUM · CVSS 4.7 EPSS 4e-05
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules0 YARA rules0
⬡

Weakness Classification

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
CWE-61UNIX Symbolic Link (Symlink) Following
▤

Affected Products & Versions

1
linuxfoundation onnx< 1.21.0
▤

Affected Packages

1
Language-ecosystem packages (from OSV) tied to this CVE, with the version that fixes it - the dependency-level detail NVD doesn’t carry.
PyPI onnx MODERATE fixed in 1.21.0
▣

Scoring & Timeline

4.7
MEDIUM · CVSS v3.1 · security-advisories@github.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD01 Apr 2026 · 06:16 PM
CVSS VectorCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N
SSVC triage · cisa-vulnrichment
Exploitation
none
Automatable
no
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.
⚑

Vendor Advisories

1
msrcCVE-2026-34446
🔗

References & Sources

2
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://github.com/onnx/onnx/commit/4755f8053928dce18a61db8fec71b69c74f786cbPatch
https://github.com/onnx/onnx/security/advisories/GHSA-cmw6-hcpp-c6jpVendor Advisory
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