CVE-2025-6638

Regular Expression Denial of Service (ReDoS) in huggingface/transformers

HIGH
7.5
CVSS Score
Published: September 12, 2025 at 10:46 AM UTC
Updated: June 17, 2026 at 10:02 AM UTC
1 product affected across 1 vendorTransformers

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Severity
HIGH7.5
Exploit prediction
EPSS 0.6%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.53.04.52.4
Affected range stops below 4.53.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-1333

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