CVE-2025-6921 - CVE House
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Status published Medium CVE-2025-6921

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

Vulnerability Description

The huggingface/transformers library, versions prior to 4.53.0, is vulnerable to Regular Expression Denial of Service (ReDoS) in the AdamWeightDecay optimizer. The vulnerability arises from the _do_use_weight_decay method, which processes user-controlled regular expressions in the include_in_weight_decay and exclude_from_weight_decay lists. Malicious regular expressions can cause catastrophic backtracking during the re.search call, leading to 100% CPU utilization and a denial of service. This issue can be exploited by attackers who can control the patterns in these lists, potentially causing the machine learning task to hang and rendering services unresponsive.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

huggingface

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Affected Software

huggingface/transformers
Vulnerable Versions:
unspecified

Timeline

Official Publish: September 23rd, 2025
Last Modified: September 23rd, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Weaknesses (CWE)