Vulnerability · Published May 19, 2025 · Assigned by @huntr_ai
CVE-2025-2099Regular Expression Denial of Service (ReDoS) in huggingface/transformers
Medium 5.3
In plain English
A medium-severity regular-expression denial of service in huggingface/transformers from huggingface. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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) attack. The regular expression used to process code blocks in docstrings contains nested quantifiers, leading to exponential backtracking when processing input with a large number of newline characters. An attacker can exploit this by providing a specially crafted payload, causing high CPU usage and potential application downtime, effectively resulting in a Denial of Service (DoS) scenario.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | transformers | 4.50.0 | GHSA-qq3j-4f4f-9583 |
| PyPI | transformers | 4.49.0 | PYSEC-2025-40 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| huggingface | huggingface/transformers | unspecified – before 4.50.0 |
Weakness: CWE-1333 · Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L