Security Resilience

CVE-2024-12720

Huggingface Transformers ≤ 4.48.0

Published
20 March 2025
Modified
01 August 2025
Patch / advisory
CVSS Score v3.1 7.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0075 54th percentile
Risk Priority 59 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2024-12720 is a high-severity Inefficient Regular Expression Complexity (CWE-1333) vulnerability in Huggingface Transformers. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked in the top 46% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

This vulnerability is AI-related — categorised as NLP and Transformers; in the Data-Related Vulnerabilities risk domain.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2024-12720 is a Regular Expression Denial of Service (ReDoS) vulnerability in the Hugging Face transformers library, specifically within the tokenization_nougat_fast.py file's post_process_single() function. The issue arises from a regular expression that exhibits exponential time complexity due to excessive backtracking when processing specially crafted input, resulting in high CPU usage and potential application downtime. This affects version v4.46.3, which was the latest at the time of disclosure, and is rated with a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), mapped to CWE-1333.

The vulnerability can be exploited by any remote attacker with network access, requiring low attack complexity, no privileges, and no user interaction. By supplying malicious input to the vulnerable function, an attacker triggers the ReDoS condition, causing severe resource exhaustion and denial of service that disrupts application availability.

Mitigation is available via a patch in the transformers repository at commit deac971c469bcbb182c2e52da0b82fb3bf54cccf. Security practitioners should update to a version incorporating this fix. The issue was disclosed through Huntr, with bounty details at https://huntr.com/bounties/4bed1214-7835-4252-a853-22bbad891f98.

This vulnerability is particularly relevant to AI/ML workflows, as the transformers library is a core component for natural language processing models, underscoring the need to validate inputs in ML tokenization pipelines.

EU & UK References

Vulnerability Data

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…

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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).

CWE(s)

AI Security AnalysisAI

AI Category
NLP and Transformers
Risk Domain
Data-Related Vulnerabilities
OWASP Top 10 for LLMs 2025
None mapped
Classification Reason
Matched keywords: huggingface, transformers

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
T1003.006 DCSync Credential Access
Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
T1008 Fallback Channels Command And Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
T1012 Query Registry Discovery
Adversaries may interact with the Windows Registry to gather information about the system, configuration, and installed software.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-3933Same product: Huggingface Transformers
CVE-2025-6638Same product: Huggingface Transformers
CVE-2025-1194Same product: Huggingface Transformers
CVE-2025-3262Same product: Huggingface Transformers
CVE-2025-3264Same product: Huggingface Transformers
CVE-2025-3263Same product: Huggingface Transformers
CVE-2025-2099Same product: Huggingface Transformers
CVE-2025-6051Same product: Huggingface Transformers
CVE-2025-5197Same product: Huggingface Transformers
CVE-2026-4372Same product: Huggingface Transformers

Affected Assets

huggingface
transformers
≤ 4.48.0

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation can discover inefficient regex patterns via performance or static analysis.

Development standards and tools can require safe regex construction and forbid known exponential patterns.

Denial-of-service protections limit resource exhaustion caused by expensive regex evaluation.

Input validation can constrain data that would otherwise trigger worst-case regex complexity.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

ID.RA-01 partial match
blocks

Vulnerability identification processes can discover ReDoS issues in existing code but do not stop their introduction.

PR.PS-06 partial match
blocks

Secure SDLC practices directly prevent inefficient regex via reviews, static analysis, and safe libraries.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

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References