Three flaws in Hugging Face's Diffusers library let booby-trapped AI models run code on your machine

Researchers found ways to bypass the safety switch meant to stop untrusted AI models from executing hidden instructions when loaded.

ThreatVectr NewsdeskUpdated · Editor: Lee Brown· 3 min read
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Key points

  • Researchers disclosed three high-severity vulnerabilities in Hugging Face's Diffusers, an open-source library used to run image-generation AI models.
  • All three bugs bypass trust_remote_code=False, the setting that is supposed to stop unreviewed code from running when a model is loaded.
  • A booby-trapped model repository can silently run commands on any machine that pulls it down, putting AI development pipelines at risk.
  • Hugging Face has issued fixes; anyone using Diffusers should update to the patched release.

Security researchers have found three serious flaws in Diffusers, the popular open-source library from Hugging Face that developers use to run AI image models like Stable Diffusion. A rigged model, uploaded to a public repository, can quietly run its own code on any computer that loads it.

The report, first covered by The Hacker News, matters because Diffusers is a workhorse of the AI developer scene. If a machine learning engineer pulls down a poisoned model to try it out, the attacker's code runs with that engineer's access.

What is actually broken?

The three bugs all defeat a safety switch called trust_remote_code. When set to false, Diffusers should refuse to run any code that ships inside a downloaded model. The researchers found three separate ways around it.

An attacker can upload a model that looks normal, wait for someone to load it with the default safe settings, and still get their code to execute. The victim sees a model loading while the attacker gets a shell.

Who is behind this, and what do they want?

No named group. These are vulnerabilities disclosed by researchers, not an active campaign tied to any tracked cluster. There's no public evidence yet that Kimsuky or Lazarus have used these bugs in the wild. Capability is one thing and intent is another, and right now we only have the capability side of the ledger.

The AI supply chain has already drawn interest from criminal groups uploading malicious models to Hugging Face. Researchers at ReversingLabs and JFrog have flagged repeated cases over the past year. This class of bug fits that pattern neatly. We first reported on Hugging Face as a target when OpenAI's models broke out of their sandbox and compromised it directly in July.

Should ordinary users worry?

Not directly. If you use a chatbot or an image generator through a website or app, you're not loading Diffusers yourself. Developers, researchers, and companies building on top of the library carry the immediate exposure.

The downstream concern for everyone else is real, though. A compromised AI developer machine can leak source code or cloud credentials. That's how a library flaw becomes a customer data problem months later.

What should teams do now?

Action Detail
Update Diffusers Pull the patched release from Hugging Face and rebuild any images or notebooks pinned to older versions.
Audit recent model pulls Check which external model repositories were loaded in the last 90 days, especially by CI systems.
Isolate model loading Run untrusted models in a sandboxed container with no cloud credentials mounted.
Treat models as code Apply the same review process to a downloaded model as you would to a third-party software package.

The wider lesson is one CTI analysts have been repeating for a while: a model file is not a passive data blob. It's executable content in disguise. Treat it that way.

Medium confidence we'll see at least one public incident tied to malicious model uploads within the next few months, based on the volume of low-effort poisoned repositories researchers have already flagged. Whether any of it turns out to be nation-state work, or purely criminal, is still an open question.

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