Simon Willison’s Weblog

Subscribe

Thursday, 23rd July 2026

The Python Package Index (PyPI) now rejects new files being uploaded to releases that are older than 14 days. This restriction was put in place to prevent old and long-stable releases from being poisoned in case publishing tokens or workflows of PyPI projects were compromised. As far as we are aware this has not yet been abused, but there is no technical reason beyond that attackers weren't aware it was possible.

Seth Larson, PyPI blog

# 4:50 am / packaging, pypi, python, supply-chain, seth-michael-larson

The first known runaway AI agent—or a very bad marketing stunt? (via) Martin Alderson's commentary on the OpenAI accidental cyberattack against Hugging Face includes a couple of details I hadn't considered.

First, Hugging Face offers a truly rich target if you're trying to find potential vulnerabilities that require executing arbitrary code:

Hugging Face has an enormous attack surface. They have more interfaces than I can count which run untrusted models and code. While they definitely have invested in defences, by nature of their operating model they do have many more opportunities to be attacked than many other services. I certainly don't envy their cybersecurity teams.

Secondly, one of the things that has puzzled me is how OpenAI didn't notice that their sandbox had been so thoroughly breached by the agent. Surely they'd be monitoring network traffic closely?

Martin points out that:

It's also likely they were running a huge amount of benchmarks simultaneously with ~unlimited token budgets - you want as many samples as possible to figure out how good a model is at a certain benchmark. It may also be they are testing various different checkpoints of the model too, understanding how the model is improving as it goes through the various training stages.

The mistakes made by the OpenAI team running this benchmark are easier to imagine when you think about the scale at which benchmarks of this kind usually operate. For all we know they could have been subjecting a new model to dozens of benchmarks at the same time, in dozens of different environments.

# 10:53 pm / security, ai, openai, generative-ai, llms, hugging-face, ai-security-research

Wednesday, 22nd July 2026

2026 » July

MTWTFSS
  12345
6789101112
13141516171819
20212223242526
2728293031