Read the docs
TI-2025-01837 Aliases CVE-2025-2099GHSA-qq3j-4f4f-9583

Regular Expression Denial of Service (ReDoS) in huggingface/transformers

Priority HIGH 72CWE-1333Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 1 fixed, 1 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-1333.

Summary

A vulnerability in the `preprocess_string()` function of the `transformers.testing_utils` module in huggingface/transformers version v4.48.3 allows for a Regular Expression Denial of Service (ReDoS) attack. The regular expression used to process code blocks in docstrings contains nested quantifiers, leading to exponential backtracking when processing input with a large number of newline characters. An attacker can exploit this by providing a specially crafted payload, causing high CPU usage and potential application downtime, effectively resulting in a Denial of Service (DoS) scenario.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00603 49th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial huggingface/transformers (huggingface): 4.50.0transformers (PyPI): 4.50.0Red Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
huggingfacehuggingface/transformersbefore 4.50.04.50.0Patch availableCNA
—transformers (PyPI)before 4.50.04.50.0Patch availableGHSA-qq3j-4f4f-9583
  • huggingface/transformers Vendorhuggingface Affected before 4.50.0 Fixed in 4.50.0 Patch available CNA
  • transformers (PyPI) Vendor— Affected before 4.50.0 Fixed in 4.50.0 Patch available GHSA-qq3j-4f4f-9583

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:huggingface:transformers:*:*:*:*:*:*:*:*up to 4.48.3Vulnerablehuggingface
  • cpe:2.3:a:huggingface:transformers:*:*:*:*:*:*:*:* Versions up to 4.48.3 Vulnerable ·huggingface

Remediation

  • Fix · CNA huggingface/transformers (huggingface) Fixed in 4.50.0
  • Fix · GHSA-qq3j-4f4f-9583 transformers (PyPI) Fixed in 4.50.0 Advisory →

Red Hat 1 advisory

  • RHSA-2025:12791 Released 2025-08-04 · Red Hat rating Moderate
    Red Hat Ansible Automation Platform 2.5 Container Release Update
    • Red Hat Ansible Automation Platform 2.5 for RHEL 8 ansible-automation-platform-25/lightspeed-chatbot-rhel8

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux AI (RHEL AI)AffectedNo fix yet
Red Hat Ansible Automation Platform 2.5 for RHEL 8Fixed RHSA-2025:12791
Not affected: 6 products
  • OpenShift Lightspeed
  • Red Hat Ansible Automation Platform 2
  • Red Hat Ansible Automation Platform 2.5 for RHEL 8
  • Red Hat Ansible Automation Platform 2.5 for RHEL 9
  • Red Hat Enterprise Linux AI (RHEL AI)
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-2099
  2. 2026-10-03 Alias added: GHSA-qq3j-4f4f-9583

References

Exploit 1

Patch 1

Advisory 1

Other 3

  • 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-2024-11793 Regular Expression Denial of Service (ReDoS) in huggingface/transformers CVSS 3.1HIGH 7.5
  • TI-2026-01514 Arbitrary Code Execution via Unsafe torch.load() in Trainer Checkpoint Loading in huggingface/transformers CVSS 3.1HIGH 7.8
See all 29 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences