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Fencer Vulns
medium 5.3

CVE-2025-3264 json

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

published 2025-07-07 16 mo ago modified 2026-07-07 4 mo ago also GHSA-jjph-296x-mrcr , PYSEC-2026-1985 , EUVD-2025-20214

cvss
5.3
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically in the `get_imports()` function within `dynamic_module_utils.py`. This vulnerability affects versions 4.49.0 and is fixed in version 4.51.0. The issue arises from a regular expression pattern `\s*try\s*:.*?except.*?:` used to filter out try/except blocks from Python code, which can be exploited to cause excessive CPU consumption through crafted input strings due to catastrophic backtracking. This vulnerability can lead to remote code loading disruption, resource exhaustion in model serving, supply chain attack vectors, and development pipeline disruption.

Patch / fix

  • pypi transformers 4.51.0
  • huggingface huggingface/transformers 4.51.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-3264 updated cvss 5.3

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

  • Red Hat OpenShift Lightspeed openshift-lightspeed/lightspeed-service-api-rhel9, openshift-lightspeed-tech-preview/lightspeed-rag-tool-rhel9 Red Hat AI Inference Server rhaiis/vllm-cuda-rhel9, rhaiis/vllm-rocm-rhel9 Red Hat Ansible Automation Platform 2 ansible-automation-platform-24/de-minimal-rhel8, ansible-automation-platform-24/de-minimal-rhel9, ansible-automation-platform-25/de-minimal-rhel8, ansible-automation-platform-25/de-minimal-rhel9, ansible-automation-platform-24/ee-supported-rhel8, ansible-automation-platform-24/ee-supported-rhel9, +5 more Red Hat Enterprise Linux AI (RHEL AI) rhelai1/gemma-2-9b-it, rhelai1/bootc-amd-rhel9, rhelai1/bootc-intel-rhel9, rhelai1/gemma-2-9b-it-fp8, rhelai1/skills-adapter-v3, rhelai1/bootc-nvidia-rhel9, +24 more Red Hat OpenShift AI (RHOAI) rhoai/odh-mm-rest-proxy-rhel9, rhoai/odh-model-registry-rhel9, rhoai/odh-kueue-controller-rhel9, rhoai/odh-mlmd-grpc-server-rhel9, rhoai/odh-training-operator-rhel8, rhoai/odh-training-operator-rhel9, +9 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
16 mo ago

Exploit prediction

0.50% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • huntr.com https://huntr.com/bounties/3c6f7822-9992-476d-8cf0-b0b1623427df referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
GitHub 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
OSV 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
pypi transformers
<4.51.0
4.51.0

Affected products

  • huggingface huggingface/transformers

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.