What’s Vulnerable › Vulnerabilities

CVE-2021-32670: Reflected cross-site scripting issue in Datasette

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.0% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-07 · updated 2026-06-17
• Weakness: CWE-79

Description

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](https://owasp.org/www-community/attacks/xss/#reflected-xss-attacks) vulnerability. This vulnerability is particularly relevant if your Datasette installation includes authenticated features using plugins such as [datasette-auth-passwords](https://datasette.io/plugins/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.

Affected products

• simonw datasette: before 0.56.1 — fixed in 0.56.1

How to fix

Upgrade to a fixed version: simonw datasette 0.56.1. Check the vendor advisory for mitigations.

References

• https://datasette.io/plugins/datasette-auth-passwords
• https://github.com/simonw/datasette/issues/1360
• https://github.com/simonw/datasette/security/advisories/GHSA-xw7c-jx9m-xh5g
• https://owasp.org/www-community/attacks/xss/#reflected-xss-attacks
• https://pypi.org/project/datasette/
• https://datasette.io/plugins/datasette-auth-passwords
• https://github.com/simonw/datasette/issues/1360
• https://github.com/simonw/datasette/security/advisories/GHSA-xw7c-jx9m-xh5g
• https://owasp.org/www-community/attacks/xss/#reflected-xss-attacks
• https://pypi.org/project/datasette/

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