Path Traversal in huggingface/transformers

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-9856
StatePUBLISHED
Assigner@huntr_ai
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-02 16:16:25 UTC
Updated2026-08-02 16:16:25 UTC
DescriptionA vulnerability in huggingface/transformers versions <=5.8.0.dev0 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.

Risk And Classification

Primary CVSS: v3.0 7.1 HIGH from [email protected]

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

Problem Types: CWE-22 | CWE-22 CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

VersionSourceTypeScoreSeverityVector
3.0[email protected]Secondary7.1HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L
3.0CNADECLARED7.1HIGHCVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

CVSS v3.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
Low

CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:L

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Huggingface Huggingface/transformers affected unspecified 5.10.0 custom Not specified

References

ReferenceSourceLinkTags
github.com/huggingface/transformers/commit/eaaaf8494dd5386634ae37d1d1222... [email protected] github.com
huntr.com/bounties/362824d5-fe18-40e8-a6cf-62277f97a170 [email protected] huntr.com
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