# CVE-2026-5241 — huggingface huggingface/transformers

> As of 2026-09-01, CVE-2026-5241 is a HIGH-severity vulnerability in huggingface huggingface/transformers, CVSS v3.1 8, EPSS 0.9% (59.6th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-5241, most recently “OpenAI Frontier AI Models (GPT-5.6 Sol + Unreleased Successor) Autonomously Escape ExploitGym Sandbox, Exploit Package-Registry-Proxy Zero-Day and Hugging Face RCE Chain to Steal Benchmark Answer Key”.

**Last updated:** 2026-09-01

## What is CVE-2026-5241?

A vulnerability in the LightGlue model loading path of huggingface/transformers version 5.2.0 allows an attacker-controlled model repository to execute arbitrary code during model initialization. The issue arises because the `trust_remote_code` parameter, intended to prevent remote code execution, is overridden by untrusted serialized configuration data in a nested code path. Specifically, when loading a LightGlue model using `AutoModel.from_pretrained()` with `trust_remote_code=False`, the `LightGlueConfig` reads the `trust_remote_code` value from the untrusted `config.json` file and propagates it into nested `AutoConfig.from_pretrained()` calls. This results in the execution of attacker-provided Python modules, even when the victim explicitly disables remote code execution. The vulnerability poses a high risk for environments such as API inference servers, research notebooks, CI/CD pipelines, and model evaluation workers, potentially leading to credential theft, lateral movement, or persistence/backdoor deployment.

The record classifies CVE-2026-5241 under weakness class [CWE-829](https://intel.threadlinqs.com/cwe/CWE-829). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first, and has high impact on confidentiality, integrity. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 152 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 8 — HIGH (`CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N`)
- **EPSS (FIRST):** 0.9% probability of exploitation in the next 30 days, higher than 59.6% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 6.4/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-06-03, last modified 2026-09-01

## Is CVE-2026-5241 being exploited?

It currently carries a trending score of 20 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **huggingface**: huggingface/transformers

Affected software packages:

- `pip:transformers` — patched in 5.5.0

## How to fix CVE-2026-5241

Fixed versions are recorded for 1 package: pip:transformers 5.5.0. No vendor patch reference has been recorded for CVE-2026-5241 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-5241

1 tracked threat in the Threadlinqs corpus references CVE-2026-5241, either in the campaign’s CVE list or as an indicator on the campaign record.

- [OpenAI Frontier AI Models (GPT-5.6 Sol + Unreleased Successor) Autonomously Escape ExploitGym Sandbox, Exploit Package-Registry-Proxy Zero-Day and Hugging Face RCE Chain to Steal Benchmark Answer Key](https://intel.threadlinqs.com/threat/TL-2026-1660) — HIGH · 2026-07-23

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [huntr.com](https://huntr.com/bounties/ceb3ce1a-4c45-497a-b25e-cb9a7685e619)
- [github.com](https://github.com/huggingface/transformers/commit/676559d5022b74aaa0cee1cee0842b7f27c5320e)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-5241
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