CVE-2026-80047: Transformers Hugging Face Transformers Downloads Custom Vulnerability

HIGH
Advisory Identifier: GHSA-x9r9-c232-4q39
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CVSS 7.8
CWE-273
Published
Advisory Summary

CVE-2026-80047 is a HIGH (CVSS 7.8) hugging face transformers downloads custom vulnerability (CWE-273: Improper Check for Dropped Privileges) affecting Transformers libraries in the PyPI ecosystem. The issue involves hugging face transformers downloads custom generation code before trust consent. Remediation is available in the latest vendor maintenance releases.

CVE-2026-80047 at a Glance

CVE Identifier CVE-2026-80047
GHSA Identifier GHSA-x9r9-c232-4q39
Severity HIGH
CVSS v3.1 Base Score 7.8
CWE Classification CWE-273: Improper Check for Dropped Privileges
Affected Product Transformers
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2026-80047

To remediate this vulnerability, upgrade all affected Transformers dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

transformers fixed: Latest secure release 
pip install transformers>=Latest secure release
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show transformers

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-80047, inspect your installed packages using pip:

pip show transformers

Analyze the terminal output to locate any version of Transformers in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The pip show transformers command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-273: Improper Check for Dropped Privileges, where the product attempts to drop privileges but does not check or incorrectly checks to see if the drop succeeded. In Transformers, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A vulnerability in Hugging Face Transformers (versions 4.49.0, <= 5.8.1) allows remote Python files to be written to local disk without user consent when using GenerativePreTrainedModel.load_custom_generate(). The function fetches and caches a remote module file before performing the required trust_remote_code consent check, inverting the security model enforced by other code-loading paths (such as AutoConfig, AutoModel, and AutoTokenizer). As a result, attacker‑controlled Python code from custom_generate/generate.py is copied into the user’s ~/.cache/huggingface/modules directory even if the user declines the trust prompt. Although execution is correctly gated, the file write is not reversible and can persist across sessions. This can lead to persistent, unauthorized files on disk and stale cache collisions where cached attacker code may later be executed during trusted model loads. The issue stems from an unconditional file write in dynamic_module_utils.py prior to any trust verification.

CVE-2026-80047 Affected Transformers Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
transformers
pypi/transformers
PyPI
≥ 4.49.0
≤ 5.8.1

References

NVD — CVE-2026-80047 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-80047
Transformers Source Repository REPOSITORY
https://github.com/huggingface/transformers/pull/48620
Security Fix Commit FIX COMMIT
https://github.com/huggingface/transformers/commit/cbc1651a032b923da7f4b44b3d0e6f68e6ba6b55
Transformers Source Repository REPOSITORY
https://github.com/huggingface/transformers
kb.cert.org/vuls/id/456290 WEB
https://kb.cert.org/vuls/id/456290
www.kb.cert.org/vuls/id/456290 WEB
https://www.kb.cert.org/vuls/id/456290

Frequently Asked Questions

What is CVE-2026-80047?
CVE-2026-80047 is a security vulnerability in Transformers involving Hugging Face Transformers downloads custom generation code before trust consent under CWE-273: Improper Check for Dropped Privileges.
Which Transformers versions are affected?
Affected versions include releases prior to current release patches across affected packages: transformers.
What version fixes CVE-2026-80047?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is transformers affected?
Yes, transformers is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-80047?
CVE-2026-80047 has a CVSS v3.1 base score of 7.8 (HIGH) with vector string CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2026-80047?
CVE-2026-80047 is classified under CWE-273: Improper Check for Dropped Privileges (The product attempts to drop privileges but does not check or incorrectly checks to see if the drop succeeded.).
How can I check PyPI dependencies for CVE-2026-80047?
Run the dependency tree command: 'pip show transformers'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
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  "schema_version" : "1.4.0",
  "id" : "GHSA-x9r9-c232-4q39",
  "modified" : "2026-09-30T23:40:28Z",
  "published" : "2026-09-01T15:31:13Z",
  "aliases" : [ "CVE-2026-80047" ],
  "summary" : "Hugging Face Transformers downloads custom generation code before trust consent",
  "details" : "A vulnerability in Hugging Face Transformers (versions 4.49.0, <= 5.8.1) allows remote Python files to be written to local disk without user consent when using GenerativePreTrainedModel.load_custom_generate(). The function fetches and caches a remote module file before performing the required trust_remote_code consent check, inverting the security model enforced by other code-loading paths (such as AutoConfig, AutoModel, and AutoTokenizer). As a result, attacker‑controlled Python code from custom_generate/generate.py is copied into the user’s ~/.cache/huggingface/modules directory even if the user declines the trust prompt. Although execution is correctly gated, the file write is not reversible and can persist across sessions. This can lead to persistent, unauthorized files on disk and stale cache collisions where cached attacker code may later be executed during trusted model loads. The issue stems from an unconditional file write in dynamic_module_utils.py prior to any trust verification.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
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  "references" : [ {
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  } ],
  "database_specific" : {
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    "nvd_published_at" : "2026-09-01T14:17:41Z"
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}