# CVE-2026-55093: tract-nnef: integer overflow in NNEF `.dat` tensor parser yields an out-of-bounds read on model load

> An integer overflow in the NNEF tensor parser allows attackers to read adjacent memory or crash the application when loading crafted models.

- **Severity:** Medium 6.1 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 14 Sep 2026
- **Updated:** 14 Sep 2026
- **Also known as:** GHSA-x5mv-8wgw-29hg, RUSTSEC-2026-0217

## What is CVE-2026-55093?

CVE-2026-55093 is a medium-severity vulnerability in sonos tract, published on 14 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

### Official description

Tract is a tiny, no-nonsense, self-contained TensorFlow and ONNX inference toolkit. Prior to 0.21.16, 0.22.2, and 0.23.1, tract-nnef uses unchecked usize multiplication in nnef/src/tensors.rs read_tensor for attacker-controlled tensor dimensions, the allocation size, and the reported tensor length. Loading a crafted NNEF archive through model_for_path or model_for_read reaches the default DatLoader and can make the wrapped size check accept a small allocation while data/src/tensor.rs as_slice_unchecked creates a much larger logical slice. Model construction through as_uniform can then read beyond the heap allocation and disclose adjacent data, and later access can terminate the process with a segmentation fault. The affected dense numeric tensor path does not include the independently guarded bool, String, or block-quant paths, and no out-of-bounds write or code execution was demonstrated. This issue is fixed in versions 0.21.16, 0.22.2, and 0.23.1.

Weakness: CWE-190 (Integer Overflow or Wraparound), CWE-125 (Out-of-bounds Read)

## Which versions are affected by CVE-2026-55093?

7 open source packages ship an affected version, including tract-nnef.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `tract-nnef` | crates.io | All versions | 0.21.16 |
| `tract-nnef` | crates.io | All versions | 0.21.16 |
| `tract-nnef` | crates.io | From 0.0.0-0 | 0.21.16, 0.22.2, 0.23.1 |
| `tract-nnef` | crates.io | From 0.22.0 | 0.22.2 |
| `tract-nnef` | crates.io | From 0.22.0 | 0.22.2 |
| `tract-nnef` | crates.io | From 0.23.0 | 0.23.1 |
| `tract-nnef` | crates.io | From 0.23.0 | 0.23.1 |

## How do I fix CVE-2026-55093?

Upgrade tract-nnef to a fixed version for your release line: 0.21.16, 0.22.2 or 0.23.1.

## Is CVE-2026-55093 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55093 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55093 and fix it if it is affected.

What it is: CVE-2026-55093 is a medium-severity vulnerability in sonos tract, published on 14 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55093 exists.

Affected packages and fixed versions:
- tract-nnef (crates.io): affected all versions; fixed in 0.21.16
- tract-nnef (crates.io): affected all versions; fixed in 0.21.16
- tract-nnef (crates.io): affected from 0.0.0-0; fixed in 0.21.16, 0.22.2, 0.23.1
- tract-nnef (crates.io): affected from 0.22.0; fixed in 0.22.2
- tract-nnef (crates.io): affected from 0.22.0; fixed in 0.22.2
- tract-nnef (crates.io): affected from 0.23.0; fixed in 0.23.1
- tract-nnef (crates.io): affected from 0.23.0; fixed in 0.23.1

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55093/ (Markdown: https://insights.sbomify.com/CVE-2026-55093/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55093
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55093
- OSV: https://osv.dev/vulnerability/CVE-2026-55093

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55093/
Summaries are generated and may contain mistakes; the official description above is the record.