Hugging Face Transformers downloads custom generation code before trust consent

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-80047: 0.10% estimated exploitation activity in the next 30 days; percentile 0.79 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.loadcustomgenerate(). The function fetches and caches a remote module file before performing the required trustremotecode 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 customgenerate/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 dynamicmoduleutils.py prior to any trust verification.

Published by the source

1 Sep 2026, 15:31 UTC

Last modified by the source

30 Sep 2026, 23:40 UTC

Source last checked

26 Oct 2026, 13:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-x9r9-c232-4q39

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2026-80047

Advisory: Hugging Face Transformers downloads custom generation code before trust consent
IDs: CVE-2026-80047, GHSA-x9r9-c232-4q39
Record: https://patchnext.com/advisories/cve-2026-80047 (revision 1, source checked 26 Oct 2026, 13:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor response not established. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI transformers: affected >= 4.49.0, <= 5.8.1

## Suggested inspection (read-only)
- `python -m pip show transformers`: prints the installed version. Run with the environment that serves production active.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on transformers.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-x9r9-c232-4q39 (GitHub-reviewed advisory GHSA-x9r9-c232-4q39 lists affected ranges: PyPI transformers >=4.49.0 <=5.8.1)

Commands are suggestions: review each one before running it.