Datasette is an open source multi-tool for exploring and publishing data. The ?_trace=1 debugging feature in Datasette does not correctly escape generated HTML, resulting in a reflected cross-site scripting vulnerability. This vulnerability is particularly relevant if your Datasette installation includes authenticated features using plugins such as datasette-auth-passwords as an attacker could use the vulnerability to access protected data.

Datasette 0.57 and 0.56.1 both include patches for this issue. If you run Datasette behind a proxy you can workaround this issue by rejecting any incoming requests with ?_trace= or &_trace= in their query string parameters.