PYSEC-2026-41

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/diffusers/PYSEC-2026-41.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-41
Aliases
Published
2026-05-14T17:16:23Z
Modified
2026-05-20T09:18:56Z
Severity
  • 8.8 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H CVSS Calculator
Summary
[none]
Details

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.

References

Affected packages

PyPI / diffusers

Package

Name
diffusers
View open source insights on deps.dev
Purl
pkg:pypi/diffusers

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
0.38.0

Affected versions

0.*
0.0.1
0.0.2
0.0.3
0.0.4
0.1.0
0.1.1
0.1.2
0.1.3
0.2.0
0.2.1
0.2.2
0.2.3
0.2.4
0.3.0
0.4.0
0.4.1
0.4.2
0.5.0
0.5.1
0.6.0
0.7.0
0.7.1
0.7.2
0.8.0
0.8.1
0.9.0
0.10.0
0.10.1
0.10.2
0.11.0
0.11.1
0.12.0
0.12.1
0.13.0
0.13.1
0.14.0
0.15.0
0.15.1
0.16.0
0.16.1
0.17.0
0.17.1
0.18.0
0.18.1
0.18.2
0.19.0
0.19.1
0.19.2
0.19.3
0.20.0
0.20.1
0.20.2
0.21.0
0.21.1
0.21.2
0.21.3
0.21.4
0.22.0
0.22.1
0.22.2
0.22.3
0.23.0
0.23.1
0.24.0
0.25.0
0.25.1
0.26.0
0.26.1
0.26.2
0.26.3
0.27.0
0.27.1
0.27.2
0.28.0
0.28.1
0.28.2
0.29.0
0.29.1
0.29.2
0.30.0
0.30.1
0.30.2
0.30.3
0.31.0
0.32.0
0.32.1
0.32.2
0.33.0
0.33.1
0.34.0
0.35.0
0.35.1
0.35.2
0.36.0
0.37.0
0.37.1

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/diffusers/PYSEC-2026-41.yaml"