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Fencer Intel
low 3.5

CVE-2025-3777 json

Improper Input Validation in huggingface/transformers

published last yr. modified last mo. also GHSA-phhr-52qp-3mj4 , PYSEC-2026-1986 , EUVD-2025-20211

cvss
3.5
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 35%
public exploits
0
none known

Summary

Hugging Face Transformers versions up to 4.49.0 are affected by an improper input validation vulnerability in the `image_utils.py` file. The vulnerability arises from insecure URL validation using the `startswith()` method, which can be bypassed through URL username injection. This allows attackers to craft URLs that appear to be from YouTube but resolve to malicious domains, potentially leading to phishing attacks, malware distribution, or data exfiltration. The issue is fixed in version 4.52.1.

Patch / fix

  • pypi transformers 4.52.1
  • huggingface huggingface/transformers 4.52.1

Is CVE-2025-3777 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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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-2025-3777 updated cvss 3.5

transformers: Improper Input Validation 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
    affected: workaround, no fix available “Fix deferred”

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
no
Technical impact
partial
Assessed
last yr.

Exploit prediction

0.41% chance of exploitation in the next 30 days, higher than 35% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • huntr.com https://huntr.com/bounties/ccba0730-9248-4853-b7ff-5c20e6364f09 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.0 3.5 CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
OSV 3.0 3.5 CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
GitHub 3.0 3.5 CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi transformers
<4.52.1
4.52.1

Affected products

  • huggingface huggingface/transformers

Classification

Weakness
  • CWE-20 Improper Input Validation

References

Sources

Fencer Intel 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.