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CVE-2025-3262· NVD / CVE Program· CNA @huntr_ai

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

A Regular Expression Denial of Service (ReDoS) vulnerability was discovered in the huggingface/transformers repository, specifically in version 4.49.0. The vulnerability is due to inefficient regular expression complexity in the `SETTING_RE` variable within the `transformers/commands/chat.py` file. The regex contains repetition groups and non-optimized quantifiers, leading to exponential backtracking when processing 'almost matching' payloads. This can degrade application performance and potentially result in a denial-of-service (DoS) when handling specially crafted input strings. The issue is fixed in version 4.51.0.

HighCVSS 7.5 · v3.1—No exploit Fix available
Published
Jul 7, 2025
Updated
Jun 17, 2026
EPSS
0.5% · 41th percentile
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Report tools

JSON

Action score

30

Monitor

Low priority for now.

CVSS
30 / 40 · 7.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.5%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
7.5
CNA · @huntr_ai
5.3
2.2 point gap

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Noroxi analysis

No Noroxi analysis for this record yet

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Affected systems

VendorProduct
huggingfacetransformers

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • huggingface transformersbefore 4.51.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (@huntr_ai). Independent of NVD's CPE analysis and usually ahead of it.

  • huggingface huggingface/transformers

    • unspecified and later · before 4.51.0affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
PyPItransformersfrom 4.49.0 · before 4.51.04.51.0

Same product

huggingface: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-3568Arbitrary Code Execution via Deserialization in huggingface/transformers
    39Monitor
  • CVE-2026-5241Policy Bypass in LightGlue Nested Config Resolution in huggingface/transformers
    38Monitor
  • CVE-2024-11392Hugging Face Transformers MobileViTV2 Deserialization of Untrusted Data Remote Code Execution Vulnerability
    37Monitor
  • CVE-2024-11394Hugging Face Transformers Trax Model Deserialization of Untrusted Data Remote Code Execution Vulnerability
    36Monitor
  • CVE-2024-11393Hugging Face Transformers MaskFormer Model Deserialization of Untrusted Data Remote Code Execution Vulnerability
    36Monitor
  • CVE-2023-6730Deserialization of Untrusted Data in huggingface/transformers
    35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
huggingface huggingface/transformers4.51.0 · descriptionVendor (CNA)
PyPI:transformers4.51.0Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-209949 days apartRegular Expression Denial of Service (ReDoS) in huggingface/transformers
    30Monitor
  • CVE-2025-663867 days apartRegular Expression Denial of Service (ReDoS) in huggingface/transformers
    30Monitor
  • CVE-2024-12720109 days apartRegular Expression Denial of Service (ReDoS) in huggingface/transformers
    30Monitor
  • CVE-2025-119469 days apartRegular Expression Denial of Service (ReDoS) in huggingface/transformers
    26Monitor
  • CVE-2025-32630 days apartRegular Expression Denial of Service (ReDoS) in huggingface/transformers
    21Monitor
  • CVE-2025-32640 days apartRegular Expression Denial of Service (ReDoS) in huggingface/transformers
    21Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-1333 · Inefficient Regular Expression Complexity

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records