Vulnerability in Huggingface Huggingface/transformers
CVE-2025-6638
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically affecting the MarianTokenizer's `remove_language_code()` method. This vulnerability is present in version 4.52.4 and has been fixed in version 4.53.0. The issue arises from inefficient regex processing, which can be exploited by crafted input strings containing malformed language code patterns, leading to excessive CPU consumption and potential denial of service.
Vulnerability class: ReDoS (Regular Expression Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (42.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: +0.000
Affected products
- Huggingface Huggingface/transformers — versions unspecified
- Huggingface Transformers — versions 4.52.4
Weakness classification (CWE)
Public proof-of-concept exploits
References
- huntr.com/bounties/6a6c933f-9ce8-4ded-8b3b-2c1444c61f36 (Exploit, Third Party Advisory)
- github.com/huggingface/transformers/commit/47c34fba5c303576560cb29767efb452ff12… (Patch)
Frequently asked questions
- What is CVE-2025-6638?
- CVE-2025-6638 is a high-severity vulnerability in Huggingface Huggingface/transformers, classified under Inefficient Regular Expression Complexity. CVSS score: 7.5/10. Published 2025-09-12.
- How severe is CVE-2025-6638?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2025-6638 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.