CVE-2025-6638

highpriority · track · 30EPSS 0.006 · 46 %ileEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.56% (46th) EPSS

CVSS 7.5 · high

Is it mine?

3 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 5.3–7.5

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 3.6

v3.05.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · ENISA EU

v3.05.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · security@huntr.devexploitability 3.9 · impact 1.4

v3.05.3mediumCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lsecondary · OSV

v3.16.9mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-1333USCWE-1333US

affected products (3)

Products and version ranges known to be affected.

huggingface huggingface/transformersunspecified → 4.53.0enisa_euvdEU
huggingface transformers= 4.52.4nvdUScpe:2.3:a:huggingface:transformers:*:*:*:*:*:*:*:*
PyPI transformers< 4.53.0osvUSpkg:pypi/transformers

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-59p9-h35m-wg4gHugging Face Transformers is vulnerable to ReDoS through its MarianTokenizer2025-09-12ghsa · osvUS
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.
PYSEC-2026-1981Hugging Face Transformers is vulnerable to ReDoS through its MarianTokenizer2026-07-07vendor · osvUS
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.

also known as (6)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2025-09-12modified 2026-06-17

references (7)

External citations — patches, advisories, analysis.

scry

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