Transformers's ReDoS vulnerability in get_configuration_file can lead to catastrophic backtracking
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the get_configuration_file() function within the transformers.configuration_utils module. The affected version is 4.49.0, and the issue is resolved in version 4.51.0. The vulnerability arises from the use of a regular expression pattern config\.(.*)\.json that can be exploited to cause excessive CPU consumption through crafted input strings, leading to catastrophic backtracking. This can result in model serving disruption, resource exhaustion, and increased latency in applications using the library.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | transformers | < 4.51.0 | 4.51.0 |
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-3263
- https://github.com/huggingface/transformers/commit/0720e206c6ba28887e4d60ef60a6a089f6c1cc76
- https://github.com/huggingface/transformers/commit/126abe3461762e5fc180e7e614391d1b4ab051ca
- https://github.com/huggingface/transformers
- https://huntr.com/bounties/c7a69150-54f8-4e81-8094-791e7a2a0f29
- https://pypi.org/project/transformers
- https://github.com/advisories/GHSA-q2wp-rjmx-x6x9
- CVSS vector
CVSS:3.0/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-2026-1987 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-q2wp-rjmx-x6x9 - 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.
- 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
- 2023: 3
- 2024: 4
- 2025: 20
- 2026: 5
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Transformers's ReDoS vulnerability in get_configuration_file can lead to catastrophic backtracking this entry
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