CVE-2026-27489: ONNX: Path Traversal via Symlink

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-04-01 · updated 2026-07-15
Weakness: CWE-23

Description

Open Neural Network Exchange (ONNX) is an open standard for machine learning interoperability. Prior to version 1.21.0, a path traversal vulnerability via symlink allows to read arbitrary files outside model or user-provided directory. This issue has been patched in version 1.21.0.

Affected products

onnx: before 1.21.0 — fixed in 1.21.0

How to fix

Upgrade to a fixed version: onnx 1.21.0. Check the vendor advisory for mitigations.

References

https://github.com/onnx/onnx/commit/4755f8053928dce18a61db8fec71b69c74f786cb
https://github.com/onnx/onnx/security/advisories/GHSA-3r9x-f23j-gc73
https://access.redhat.com/errata/RHSA-2026:24977
https://access.redhat.com/security/cve/CVE-2026-27489
https://bugzilla.redhat.com/show_bug.cgi?id=2453929
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-27489.json

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