PYSEC-2026-3929

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Import Source
https://github.com/pypa/advisory-database/blob/main/vulns/transformers/PYSEC-2026-3929.yaml
JSON Data
https://api.osv.dev/v1/vulns/PYSEC-2026-3929
Aliases
Published
2026-09-10T09:44:51Z
Modified
2026-09-10T12:15:13Z
Severity
  • 7.1 (High) CVSS_V3 - CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L CVSS Calculator
Summary
Transformers save_pretrained path traversal allows arbitrary file writes through chat template names
Details

A vulnerability in huggingface/transformers versions < 5.10.0 allows an attacker to perform arbitrary file writes via path traversal. The issue resides in the save_pretrained() methods of PreTrainedTokenizerBase and ProcessorMixin, where keys from the chat_template dictionary are used directly as filenames without proper validation. An attacker can exploit this by publishing a malicious Hugging Face Hub repository with a crafted tokenizer_config.json file. When a victim downloads and saves the tokenizer or processor, the attacker-controlled keys can escape the intended save directory, enabling arbitrary file writes with attacker-controlled content. This vulnerability affects multiple processors inheriting from ProcessorMixin, including Idefics, Florence, Gemma, Phi, and Qwen-VL.

References

Affected packages

PyPI / transformers

Package

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

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
5.10.0

Affected versions

0.*
0.1
2.*
2.0.0
2.1.0
2.1.1
2.2.0
2.2.1
2.2.2
2.3.0
2.4.0
2.4.1
2.5.0
2.5.1
2.6.0
2.7.0
2.8.0
2.9.0
2.9.1
2.10.0
2.11.0
3.*
3.0.0
3.0.1
3.0.2
3.1.0
3.2.0
3.3.0
3.3.1
3.4.0
3.5.0
3.5.1
4.*
4.0.0rc1
4.0.0
4.0.1
4.1.0
4.1.1
4.2.0
4.2.1
4.2.2
4.3.0rc1
4.3.0
4.3.1
4.3.2
4.3.3
4.4.0
4.4.1
4.4.2
4.5.0
4.5.1
4.6.0
4.6.1
4.7.0
4.8.0
4.8.1
4.8.2
4.9.0
4.9.1
4.9.2
4.10.0
4.10.1
4.10.2
4.10.3
4.11.0
4.11.1
4.11.2
4.11.3
4.12.0
4.12.1
4.12.2
4.12.3
4.12.4
4.12.5
4.13.0
4.14.0
4.14.1
4.15.0
4.16.0
4.16.1
4.16.2
4.17.0
4.18.0
4.19.0
4.19.1
4.19.2
4.19.3
4.19.4
4.20.0
4.20.1
4.21.0
4.21.1
4.21.2
4.21.3
4.22.0
4.22.1
4.22.2
4.23.0
4.23.1
4.24.0
4.25.0
4.25.1
4.26.0
4.26.1
4.27.0
4.27.1
4.27.2
4.27.3
4.27.4
4.28.0
4.28.1
4.29.0
4.29.1
4.29.2
4.30.0
4.30.1
4.30.2
4.31.0
4.32.0
4.32.1
4.33.0
4.33.1
4.33.2
4.33.3
4.34.0
4.34.1
4.35.0
4.35.1
4.35.2
4.36.0
4.36.1
4.36.2
4.37.0
4.37.1
4.37.2
4.38.0
4.38.1
4.38.2
4.39.0
4.39.1
4.39.2
4.39.3
4.40.0
4.40.1
4.40.2
4.41.0
4.41.1
4.41.2
4.42.0
4.42.1
4.42.2
4.42.3
4.42.4
4.43.0
4.43.1
4.43.2
4.43.3
4.43.4
4.44.0
4.44.1
4.44.2
4.45.0
4.45.1
4.45.2
4.46.0
4.46.1
4.46.2
4.46.3
4.47.0
4.47.1
4.48.0
4.48.1
4.48.2
4.48.3
4.49.0
4.50.0
4.50.1
4.50.2
4.50.3
4.51.0
4.51.1
4.51.2
4.51.3
4.52.0
4.52.1
4.52.2
4.52.3
4.52.4
4.53.0
4.53.1
4.53.2
4.53.3
4.54.0
4.54.1
4.55.0
4.55.1
4.55.2
4.55.3
4.55.4
4.56.0
4.56.1
4.56.2
4.57.0
4.57.1
4.57.2
4.57.3
4.57.4
4.57.5
4.57.6
5.*
5.0.0rc0
5.0.0rc1
5.0.0rc2
5.0.0rc3
5.0.0
5.1.0
5.2.0
5.3.0
5.4.0
5.5.0
5.5.1
5.5.2
5.5.3
5.5.4
5.6.0
5.6.1
5.6.2
5.7.0
5.8.0
5.8.1
5.9.0

Database specific

source 
"https://github.com/pypa/advisory-database/blob/main/vulns/transformers/PYSEC-2026-3929.yaml"