What is the CVSS score of CVE-2025-6921?

CVE-2025-6921 has a CVSS 3.1 base score of 7.5 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. EPSS exploitation probability: 0.0%.

Which versions of Transformers are affected by CVE-2025-6921?

CVE-2025-6921 presents notable security risk, a resource exhaustion vulnerability rated CVSS 7.5.. A patch is available.

Is there a public PoC exploit available for CVE-2025-6921?

Yes, a public proof-of-concept exploit is available for CVE-2025-6921. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2025-6921?

Within 30 days: Identify all affected systems and apply vendor patches as part of regular patch cycle. Vendor patch is available.

Transformers CVE-2025-6921

HIGH

Uncontrolled Resource Consumption (CWE-400)

2025-09-23 security@huntr.dev

Denial Of Service Transformers Red Hat Suse

7.5

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

7.5 HIGH

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SUSE

5.3 MEDIUM

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

Red Hat

5.3 MEDIUM

qualitative

Primary rating from NVD.

CVSS VectorNVD

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

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:13 vuln.today

Patch released

Mar 28, 2026 - 19:13 nvd

Patch available

PoC Detected

Oct 10, 2025 - 21:31 vuln.today

Public exploit code

CVE Published

Sep 23, 2025 - 14:15 nvd

HIGH 7.5

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

13 pypi packages depend on transformers (13 direct, 0 indirect)

Ecosystem-wide dependent count for version 4.53.0.

DescriptionCVE.org

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.

AnalysisAI

The huggingface/transformers library, versions prior to 4.53.0, is vulnerable to Regular Expression Denial of Service (ReDoS) in the AdamWeightDecay optimizer. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified as Uncontrolled Resource Consumption (CWE-400), which allows attackers to cause denial of service by exhausting system resources. 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. Affected products include: Huggingface Transformers. Version information: prior to 4.53.0.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Implement rate limiting, set resource quotas, validate input sizes, use timeouts.