# CVE-2025-5197: PYSEC-2026-1983 - Hugging Face Transformers Regular Expression Denial of Service (ReDoS) vulnerability

Source: https://junglewise.ai/threats/cve-2025-5197-hugging-face-transformers-regular-expression-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-07-07  
License: CC BY 4.0 with a link back

CVE-2025-5197 · Severity: low · CVSS 3 · Published 2026-07-07

Hugging Face Transformers Regular Expression Denial of Service (ReDoS) vulnerability

Technologies: [transformers (PyPI)](https://junglewise.ai/threats/technologies/pypi-transformers). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2025-5197 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-5197 being exploited in the wild.

**How severe is CVE-2025-5197?** Low severity, with a CVSS score of 3, published 7 July 2026.

**Which products and versions are affected?** transformers (PyPI) ECOSYSTEM:introduced=0,fixed=4.53.0.

**Is there a fix for CVE-2025-5197?** Yes. transformers (PyPI): upgrade to 4.53.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2025-5197?** Check whether you run transformers (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- transformers (PyPI): upgrade to 4.53.0 or later

  ```sh
  pip install "transformers>=4.53.0"
  ```


## Affected products

- transformers (PyPI) ECOSYSTEM:introduced=0,fixed=4.53.0

## Identifiers

- CVE-2025-5197
- GHSA-9356-575x-2w9m
- PYSEC-2026-1983

## Related threats

- [Hugging Face Transformers arbitrary file write via load_custom_generate](https://junglewise.ai/threats/cve-2026-80047-hugging-face-transformers-arbitrary-file-write-via-load-custom)
- [Hugging Face Transformers path traversal in save_pretrained](https://junglewise.ai/threats/cve-2026-9856-hugging-face-transformers-path-traversal-in-save-pretrained)
- [Hugging Face Transformers vulnerable to Regular Expression Denial of Service (ReDoS) in the AdamWeightDecay optimizer](https://junglewise.ai/threats/cve-2025-6921-hugging-face-transformers-vulnerable-to-regular-expression-denial)
- [PYSEC-2026-1988 - Hugging Face Transformers library has Regular Expression Denial of Service](https://junglewise.ai/threats/cve-2025-6051-hugging-face-transformers-library-has-regular-expression-denial-of)
- [PYSEC-2026-1981 - Hugging Face Transformers is vulnerable to ReDoS through its MarianTokenizer](https://junglewise.ai/threats/cve-2025-6638-hugging-face-transformers-is-vulnerable-to-redos-through-its)