LOW3.5
PYSEC-2026-1986
Transformers's Improper Input Validation vulnerability can be exploited through username injection
Quick fix
PYSEC-2026-1986 — transformers: upgrade to the fixed version with the command below.
pip install --upgrade 'transformers>=4.52.1'Details
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.
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://nvd.nist.gov/vuln/detail/CVE-2025-3777[ADVISORY]
- https://github.com/huggingface/transformers/commit/4dda5f71b35fb70cf602187eef84bb17a50b9082[WEB]
- https://github.com/huggingface/transformers[PACKAGE]
- https://github.com/huggingface/transformers/blame/a7d2bbaaa8aac64f7c1ee8c1421cfe84b38359a4/src/transformers/image_utils.py[WEB]
- https://huntr.com/bounties/ccba0730-9248-4853-b7ff-5c20e6364f09[WEB]
- https://pypi.org/project/transformers[PACKAGE]
- https://github.com/advisories/GHSA-phhr-52qp-3mj4[ADVISORY]