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Medium

Transformers vulnerable to ReDoS attack through its SETTING_RE variable

  • Disclosed: 07.07.2025
  • Updated: 11.10.2026 13:19

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the huggingface/transformers repository, specifically in version 4.49.0. The vulnerability is due to inefficient regular expression complexity in the SETTING_RE variable within the transformers/commands/chat.py file. The regex contains repetition groups and non-optimized quantifiers, leading to exponential backtracking when processing 'almost matching' payloads. This can degrade application performance and potentially result in a denial-of-service (DoS) when handling specially crafted input strings. The issue is fixed in version 4.51.0.

Affected software

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PlatformPackageVulnerable versionsFixed in
Python (PyPI) transformers >= 4.49.0, < 4.51.0 4.51.0

References

CVSS score 5.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weakness (CWE)
CWE-1333
Platform
Python (PyPI)
Package
transformers
Disclosed
07.07.2025
Updated
11.10.2026 13:19

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2026-1979 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-489j-g2vx-39wf - CC BY 4.0

Vulnerability history: transformers

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (32) in the archive
Total entries
32
First → latest
05.2023 09.2026
Without a fix
9
Exploited in attacks
0

Severity breakdown

  • High 18
  • Medium 12
  • Low 2

Disclosures per year

Severity:
  1. Hugging Face Transformers downloads custom generation code before trust consent
    High · 7.8 CVE-2026-80047 >= 4.49.0, <= 5.8.1 no fix
  2. Transformers save_pretrained path traversal allows arbitrary file writes through chat template names
    High · 7.1 CVE-2026-9856 < 5.10.0 5.10.0
  3. huggingface/transformers: Arbitrary Code Execution During Model Initialization in the LightGlue Model Loading Path
    High · 8.0 CVE-2026-5241 < 5.5.0 5.5.0
  4. HuggingFace transformers vulnerable to remote code execution
    High · 7.8 CVE-2026-4372 < 5.3.0 5.3.0
  5. Hugging Face Transformers GLM4 Deserialization of Untrusted Data Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of
    High · 7.8 CVE-2025-14930 <= 4.57.1 no fix
  6. Hugging Face Transformers HuBERT convert_config Code Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Hu
    High · 7.8 CVE-2025-14928 <= 4.57.0 no fix
  7. Hugging Face Transformers X-CLIP Checkpoint Conversion Deserialization of Untrusted Data Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on af
    High · 7.8 CVE-2025-14929 <= 5.0.0-rc0 no fix
  8. Hugging Face Transformers SEW convert_config Code Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Huggi
    High · 7.8 CVE-2025-14926 <= 4.57.0 no fix
  9. Hugging Face Transformers SEW-D convert_config Code Injection Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of Hug
    High · 7.8 CVE-2025-14927 <= 4.57.0 no fix
  10. Hugging Face Transformers Perceiver Model Deserialization of Untrusted Data Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected instal
    High · 7.8 CVE-2025-14920 <= 4.54.1 no fix
  11. Hugging Face Transformers Transformer-XL Model Deserialization of Untrusted Data Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected i
    High · 7.8 CVE-2025-14921 <= 4.54.1 no fix
  12. Hugging Face Transformers megatron_gpt2 Deserialization of Untrusted Data Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installa
    High · 7.8 CVE-2025-14924 <= 4.55.0 no fix
  13. Transformers vulnerable to ReDoS attack through its SETTING_RE variable this entry
    Medium · 5.3 CVE-2025-3262 >= 4.49.0, < 4.51.0 4.51.0
  14. A vulnerability in the `preprocess_string()` function of the `transformers.testing_utils` module in huggingface/transformers version v4.48.3 allows for a Regular Expression Denial of Service (ReDoS) a
    High · 7.5 CVE-2025-2099 < 4.49.0 4.49.0
  15. Deserialization of Untrusted Data in Hugging Face Transformers
    High · 8.8 CVE-2024-11394 < 4.48.0 4.48.0
  16. Deserialization of Untrusted Data in Hugging Face Transformers
    High · 8.8 CVE-2024-11393 < 4.48.0 4.48.0
  17. Deserialization of Untrusted Data in Hugging Face Transformers
    High · 7.5 CVE-2024-11392 < 4.48.0 4.48.0
  18. Deserialization of Untrusted Data in GitHub repository huggingface/transformers prior to 4.36.
    High · 7.8 CVE-2023-7018 < 4.36.0 4.36.0
  19. Deserialization of Untrusted Data in GitHub repository huggingface/transformers prior to 4.36.
    High · 8.8 CVE-2023-6730 < 4.36.0 4.36.0

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