CVE-2025-3777 Improper Input Validation in huggingface/transformers
Attackers can bypass URL validation to redirect users to malicious domains, enabling phishing or malware distribution in Hugging Face Transformers.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-3777?
CVE-2025-3777 is a low-severity vulnerability in huggingface/transformers, published on 7 Jul 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
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.
Weakness: CWE-20
Which versions are affected by CVE-2025-3777?
3 open source packages ship an affected version, including transformers. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
transformers PyPI | All versions | 4.52.1 |
transformers PyPI | All versions | 4.52.1 |
transformers PyPI | All versions | 4.52.1 |
Products include Huggingface Transformers.
How do I fix CVE-2025-3777?
Upgrade transformers to 4.52.1 or later.
Is CVE-2025-3777 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-3777 exists.
Other vulnerabilities in huggingface/transformers
- CVE-2023-7018 Deserialization of Untrusted Data in huggingface/transformers
- CVE-2023-6730 Deserialization of Untrusted Data in huggingface/transformers
- CVE-2024-11393 Hugging Face Transformers MaskFormer Model Deserialization of Untrusted Data Remote Code Execution Vulnerability
- CVE-2024-11394 Hugging Face Transformers Trax Model Deserialization of Untrusted Data Remote Code Execution Vulnerability
- CVE-2026-5241 Policy Bypass in LightGlue Nested Config Resolution in huggingface/transformers
Sources
Also known as GHSA-phhr-52qp-3mj4, PYSEC-2026-1986.