huggingface transformers up to 4.50.x dynamic_module_utils.py get_imports redos

Summaryinfo

A vulnerability classified as problematic was found in huggingface transformers up to 4.50.x. Affected by this issue is the function get_imports of the file dynamic_module_utils.py. Such manipulation leads to redos. This vulnerability is referenced as CVE-2025-3264. It is possible to launch the attack remotely. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in huggingface transformers up to 4.50.x and classified as problematic. Affected by this issue is the function get_imports of the file dynamic_module_utils.py. The manipulation with an unknown input leads to a redos vulnerability. Using CWE to declare the problem leads to CWE-1333. The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles. Impacted is availability. CVE summarizes:

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the `get_imports()` function within `dynamic_module_utils.py`. This vulnerability affects versions 4.49.0 and is fixed in version 4.51.0. The issue arises from a regular expression pattern `\s*try\s*:.*?except.*?:` used to filter out try/except blocks from Python code, which can be exploited to cause excessive CPU consumption through crafted input strings due to catastrophic backtracking. This vulnerability can lead to remote code loading disruption, resource exhaustion in model serving, supply chain attack vectors, and development pipeline disruption.

The advisory is shared for download at huntr.com. This vulnerability is handled as CVE-2025-3264 since 04/04/2025. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1449.003.

Upgrading to version 4.51.0 eliminates this vulnerability. Applying the patch 0720e206c6ba28887e4d60ef60a6a089f6c1cc76 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-20214). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• huggingface

Name

• transformers

Version

• 4.0
• 4.1
• 4.2
• 4.3
• 4.4
• 4.5
• 4.6
• 4.7
• 4.8
• 4.9
• 4.10
• 4.11
• 4.12
• 4.13
• 4.14
• 4.15
• 4.16
• 4.17
• 4.18
• 4.19
• 4.20
• 4.21
• 4.22
• 4.23
• 4.24
• 4.25
• 4.26
• 4.27
• 4.28
• 4.29
• 4.30
• 4.31
• 4.32
• 4.33
• 4.34
• 4.35
• 4.36
• 4.37
• 4.38
• 4.39
• 4.40
• 4.41
• 4.42
• 4.43
• 4.44
• 4.45
• 4.46
• 4.47
• 4.48
• 4.49
• 4.50

License

• open-source

Website

• Product: https://github.com/huggingface/transformers/

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Once again VulDB remains the best source for vulnerability data.

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