What is CVE-2025-6921?

CVE-2025-6921 is a high-severity vulnerability in Huggingface Huggingface/transformers, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2025-09-23.

How severe is CVE-2025-6921?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2025-6921 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Resource exhaustion in Huggingface Huggingface/transformers

CVE-2025-6921

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…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.005 (37.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Huggingface Huggingface/transformers — versions unspecified
Huggingface Transformers

Weakness classification (CWE)

CWE-400 — Uncontrolled Resource Consumption

Public proof-of-concept exploits

ARPSyndicate/cve-scores

References

security@huntr.dev (Exploit, Third Party Advisory)
security@huntr.dev (Patch)

Frequently asked questions

What is CVE-2025-6921?: CVE-2025-6921 is a high-severity vulnerability in Huggingface Huggingface/transformers, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2025-09-23.
How severe is CVE-2025-6921?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2025-6921 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.