tract: Arbitrary file read via unsanitized ONNX external_data location (path traversal) on model load in tract-onnx

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.1 · CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:L

EPSS

• CVE-2026-55832: 0.19% estimated exploitation activity in the next 30 days; percentile 9.14 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary tract (the tract-onnx crate) resolves an ONNX tensor's external-data location by joining it onto the model directory without any sanitization. Because location comes from the (untrusted) .onnx file, a malicious model can make tract open and read an arbitrary local file at load time, with the file's contents flowing into the model's tensors / inference output (read-only file disclosure). This is the ONNX external-data path-traversal class that the reference onnx library hardened over several CVEs; tract resolves location itself and was never hardened. Details In onnx/src/tensor.rs, getexternalresources() builds the path with no checks: - Path::join with an absolute location (e.g. /etc/passwd) discards the base directory → p = /etc/passwd. - A relative ../../../../etc/passwd value is not normalized → directory traversal. - The default MmapDataResolver (onnx/src/dataresolver.rs) then mmaps the file and copies mmap[offset..offset+length] into the tensor. offset/length are also…

Published by the source

19 Jun 2026, 14:45 UTC

Last modified by the source

19 Jun 2026, 14:45 UTC

Source last checked

26 Oct 2026, 15:42 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h668-6x6g-f8r5

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# Patch Next advisory brief: CVE-2026-55832

Advisory: tract: Arbitrary file read via unsanitized ONNX external_data `location` (path traversal) on model load in tract-onnx
IDs: CVE-2026-55832, GHSA-h668-6x6g-f8r5
Record: https://patchnext.com/advisories/cve-2026-55832 (revision 1, source checked 26 Oct 2026, 15:42 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: tract-onnx 0.23.2, 0.22.3, 0.21.17. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io tract-onnx: affected < 0.21.17; >= 0.22.0, < 0.22.3; >= 0.23.0, < 0.23.2; fixed in 0.22.3, 0.21.17, 0.23.2

## Suggested inspection (read-only)
- crates.io tract-onnx: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on tract-onnx.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-h668-6x6g-f8r5 (GitHub-reviewed advisory GHSA-h668-6x6g-f8r5 lists affected ranges: crates.io tract-onnx >=0 =0.22.0 =0.23.0 <0.23.2)

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