CVE-2024-12720 Regular Expression Denial of Service (ReDoS) in huggingface/transformers
Attackers can cause denial of service in applications using the transformers library by submitting crafted input that triggers excessive CPU usage via regex backtracking.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-12720?
CVE-2024-12720 is a medium-severity denial of service vulnerability in huggingface/transformers, published on 20 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A Regular Expression Denial of Service (ReDoS) vulnerability was identified in the huggingface/transformers library, specifically in the file tokenization_nougat_fast.py. The vulnerability occurs in the post_process_single() function, where a regular expression processes specially crafted input. The issue stems from the regex exhibiting exponential time complexity under certain conditions, leading to excessive backtracking. This can result in significantly high CPU usage and potential application downtime, effectively creating a Denial of Service (DoS) scenario. The affected version is v4.46.3 (latest).
Weakness: CWE-1333
Which versions are affected by CVE-2024-12720?
3 open source packages ship an affected version, including transformers. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
transformers PyPI | All versions | 4.48.0 |
transformers PyPI | All versions | 4.48.0 |
transformers PyPI | All versions | 4.48.0 |
Products include Huggingface Transformers.
How do I fix CVE-2024-12720?
Upgrade transformers to 4.48.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2024-12720 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-12720 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-6rvg-6v2m-4j46, PYSEC-2026-1982.