Read the docs
TI-2026-26711 Aliases CVE-2026-34446GHSA-cmw6-hcpp-c6jp

ONNX: Arbitrary File Read via ExternalData Hardlink Bypass in ONNX load

Priority LOW 24CWE-22Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-22 and the CVSS impact.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00183 7th percentileScored 2026-11-07
Fix Partial onnx (onnx): 1.21.0onnx (PyPI): 1.21.0Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
onnxonnxbefore 1.21.01.21.0Patch availableCNA
—onnx (PyPI)before 1.21.01.21.0Patch availableGHSA-cmw6-hcpp-c6jp
  • onnx Vendoronnx Affected before 1.21.0 Fixed in 1.21.0 Patch available CNA
  • onnx (PyPI) Vendor— Affected before 1.21.0 Fixed in 1.21.0 Patch available GHSA-cmw6-hcpp-c6jp

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:linuxfoundation:onnx:*:*:*:*:*:*:*:*before 1.21.0Vulnerablebackstage
  • cpe:2.3:a:linuxfoundation:onnx:*:*:*:*:*:*:*:* Versions before 1.21.0 Vulnerable ·backstage

Remediation

  • Fix · CNA onnx (onnx) Fixed in 1.21.0
  • Fix · GHSA-cmw6-hcpp-c6jp onnx (PyPI) Fixed in 1.21.0 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34446
  2. 2026-10-03 Alias added: GHSA-cmw6-hcpp-c6jp

References

Patch 1

Advisory 2

Other 1

  • TI-2026-22763 ONNX Untrusted Model Repository Warnings Suppressed by silent=True in onnx.hub.load() — Silent Supply-Chain Attack CVSS 3.1CRITICAL 9.1
  • TI-2026-21896 ONNX: Path Traversal via Symlink CVSS 4.0HIGH 8.7
  • TI-2024-07209 Arbitrary File Overwrite in onnx/onnx CVSS 3.1CRITICAL 9.1
  • TI-2024-04814 Arbitrary File Overwrite in download_model_with_test_data in onnx/onnx CVSS 3.1HIGH 8.8
  • TI-2026-36338 ONNX symlink-following and path-traversal arbitrary file write CVSS 4.0MEDIUM 6.8
  • TI-2026-32442 ONNX: Null Pointer Dereference in Upsample Version Converter Adapter (Zero Inputs) CVSS 3.1MEDIUM 5.5
See all 16 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences