CVE-2025-6921

HIGH EPSS 37.0%
Published Sep 23, 20259mo ago · Modified Jun 17, 20261w ago
7.5 CVSS 3.1
High
Find Similar
Published Sep 23, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

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.

CVSS Details

Base Score
7.5
Exploitability
3.9
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
37.0% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-400 Uncontrolled Resource Consumption Resource Mgmt

Affected Products 1

VendorProductVersionRange
huggingfacetransformers* <4.53.0

References 2

  • github.com https://github.com/huggingface/transformers/commit/47c34fba5c303576560cb29767efb452ff12b8be
    Patch
  • huntr.com https://huntr.com/bounties/287d15a7-6e7c-45d2-8c05-11e305776f1f
    ExploitThird Party Advisory

Remediation

  • github.com https://github.com/huggingface/transformers/commit/47c34fba5c303576560cb29767efb452ff12b8be
    Patch