The Datasette project released two security patch versions, 1.0a39 for its alpha series and 0.65.4 for the stable 0.65.x branch, maintainer Simon Willison said in a post Sept. 11. Willison said anyone running a public Datasette instance should apply the fixes, particularly instances that mix public and private tables.
The issues were found by Sevban Donmez, Alex Garcia and Willison during what he described as an extensive audit. The post does not disclose the technical mechanics of the vulnerabilities, a common practice when a fix is fresh and detailed specifics could otherwise hand attackers a map before users patch.
Garcia and Willison split the audit work, with one writing an automated test that reproduced an issue and the other implementing the fix, according to the post. The review, which took about a week, also used Claude Fable 5.1, GPT-5.6 and GPT-6 Astra to help surface problems, and Willison said frontier-model security audits will become a regular part of the project's development process going forward.
Datasette instances often sit on top of real user data with an ad hoc mix of public and locked-down tables, exactly the setup this patch targets. Anyone running Datasette in production should update now rather than wait for the specifics to surface in a future writeup.