---
id: CVE-2025-3777
aliases:
  - GHSA-phhr-52qp-3mj4
  - PYSEC-2026-1986
title: >-
  Transformers's Improper Input Validation vulnerability can be exploited
  through username injection
summary: >-
  Transformers's Improper Input Validation vulnerability can be exploited
  through username injection
severity: low
cvss: 3.5
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N'
vendor: transformers
product: transformers
ecosystem: pip
affected:
  - transformers < 4.52.1
patched:
  - transformers 4.52.1
published: '2025-07-07'
updated: '2026-09-10'
sourceUpdated: '2026-09-10T03:50:26.198077196Z'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-phhr-52qp-3mj4'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-3777'
  - url: >-
      https://github.com/huggingface/transformers/commit/4dda5f71b35fb70cf602187eef84bb17a50b9082
  - url: 'https://github.com/huggingface/transformers'
  - url: >-
      https://github.com/huggingface/transformers/blame/a7d2bbaaa8aac64f7c1ee8c1421cfe84b38359a4/src/transformers/image_utils.py
  - url: 'https://huntr.com/bounties/ccba0730-9248-4853-b7ff-5c20e6364f09'
tags:
  - osv
  - pip
epss: 0.00357
epssPercentile: 0.29457
ingestedAt: '2026-07-08T18:25:51.781Z'
---

## Overview

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.

## Affected packages

- `transformers < 4.52.1`

## Remediation

Upgrade to a patched release:

- `transformers 4.52.1`