# CVE-2026-44827: Diffusers: None.py Trust Remote Code Bypass

> CVE-2026-44827: Diffusers: None.py Trust Remote Code Bypass. CVSS 8.8 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-44827
Last updated: 2026-06-17T10:51:24Z

- Published: 2026-05-14 16:33 UTC · Updated: 2026-06-17 10:51 UTC · Assigner: GitHub\_M
- CVSS: 8.8 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS: 0.72%, 54th percentile (scored 2026-10-25)
- CISA KEV: no
- CWE: CWE-94

## Description

Diffusers is the a library for  pretrained diffusion models. Prior to 0.38.0, diffusers 0.37.0 allows remote code execution without the trust\_remote\_code=True safeguard when loading pipelines from Hugging Face Hub repositories. The \_resolve\_custom\_pipeline\_and\_cls function in pipeline\_loading\_utils.py performs string interpolation on the custom\_pipeline parameter using f"{custom\_pipeline}.py". When custom\_pipeline is not supplied by the user, it defaults to None, which Python interpolates as the literal string "None.py". If an attacker publishes a Hub repository containing a file named None.py with a class that subclasses DiffusionPipeline, the file is automatically downloaded and executed during a standard DiffusionPipeline.from\_pretrained() call with no additional keyword arguments. The trust\_remote\_code check in DiffusionPipeline.download() is bypassed because it evaluates custom\_pipeline is not None as False (since the kwarg was never supplied), while the downstream code path that actually loads the module resolves the None value into a valid filename. An attacker can achieve silent arbitrary code execution by publishing a malicious model repository with a None.py file and a standard-looking model\_index.json that references a legitimate pipeline class name, requiring only that a victim calls from\_pretrained on the repository. This vulnerability is fixed in 0.38.0.

## Affected vendors and products

- huggingface: diffusers

## Tracked companies

- [Hugging Face](https://rewindex.com/company/hugging-face.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-44827)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-44827)
- [https://github.com/huggingface/diffusers/security/advisories/GHSA-j7w6-vpvq-j3gm](https://github.com/huggingface/diffusers/security/advisories/GHSA-j7w6-vpvq-j3gm)

---

_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


---
Canonical: https://rewindex.com/cve/CVE-2026-44827 · Markdown: https://rewindex.com/cve/CVE-2026-44827.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-44827 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T01:58:50.564Z