Regular Expression Denial of Service (ReDoS) in huggingface/transformers
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Partial Red Hat: 5 without a fix
Attack profile from CVSS 3.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-1333.
Summary
A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the Hugging Face Transformers library, specifically within the `normalize_numbers()` method of the `EnglishNormalizer` class. This vulnerability affects versions up to 4.52.4 and is fixed in version 4.53.0. The issue arises from the method's handling of numeric strings, which can be exploited using crafted input strings containing long sequences of digits, leading to excessive CPU consumption. This vulnerability impacts text-to-speech and number normalization tasks, potentially causing service disruption, resource exhaustion, and API vulnerabilities.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| huggingface | huggingface/transformers | before 4.53.0 | 4.53.0 | Patch available | CNA |
| — | transformers (PyPI) | before 4.53.0 | 4.53.0 | Patch available | GHSA-rcv9-qm8p-9p6j |
- huggingface/transformers Vendorhuggingface Affected before 4.53.0 Fixed in 4.53.0 Patch available CNA
- transformers (PyPI) Vendor— Affected before 4.53.0 Fixed in 4.53.0 Patch available GHSA-rcv9-qm8p-9p6j
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:huggingface:transformers:4.52.4:*:*:*:*:*:*:* | 4.52.4 | Vulnerable | huggingface |
- cpe:2.3:a:huggingface:transformers:4.52.4:*:*:*:*:*:*:* Versions 4.52.4 Vulnerable ·huggingface
Remediation
- Fix · CNA huggingface/transformers (huggingface) Fixed in 4.53.0
- Fix · GHSA-rcv9-qm8p-9p6j transformers (PyPI) Fixed in 4.53.0 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| OpenShift Lightspeed | Affected | No fix yet: Fix deferred |
| Red Hat AI Inference Server | Affected | No fix yet: Fix deferred |
| Red Hat Ansible Automation Platform 2 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux AI (RHEL AI) | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift AI (RHOAI) | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-02 Threatist record created from CVE-2025-6051
- 2026-10-03 Alias added: GHSA-rcv9-qm8p-9p6j
References
More huggingface Transformers vulnerabilities
- TI-2026-04577 Policy Bypass in LightGlue Nested Config Resolution in huggingface/transformers CVSS 3.1CRITICAL 9.6
- TI-2025-06294 Regular Expression Denial of Service (ReDoS) in huggingface/transformers CVSS 3.1HIGH 7.5
- TI-2025-06027 Regular Expression Denial of Service (ReDoS) in huggingface/transformers CVSS 3.1HIGH 7.5
- TI-2025-02858 Regular Expression Denial of Service (ReDoS) in huggingface/transformers CVSS 3.1HIGH 7.5
- TI-2025-01837 Regular Expression Denial of Service (ReDoS) in huggingface/transformers CVSS 3.1HIGH 7.5
- TI-2024-11793 Regular Expression Denial of Service (ReDoS) in huggingface/transformers CVSS 3.1HIGH 7.5
Sources
- CVE-2025-6051 · CVE Program
- CVE-2025-6051 · NVD
- FIRST EPSS
- GHSA-rcv9-qm8p-9p6j · GitHub Advisory Database · CC BY 4.0
- CVE-2025-6051 · Red Hat security data · CC BY 4.0
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