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

Summary The issue is in onnx.load — the code checks for symlinks to prevent path traversal, but completely misses hardlinks, which is the problem, since a hardlink looks exactly like a regular file on the filesystem. The Real Problem The validator in onnx/checker.cc only calls issymlink and never...

CVE-2026-34446

CVE-2026-34446 affects Open Neural Network Exchange (ONNX). The vulnerability is in onnx.load where hardlinks can bypass the path-traversal check, allowing an arbitrary file read. The issue is fixed in ONNX 1.21.0. Impact is described as arbitrary file read with LOCAL attack vector and MEDIUM bas...