Beets · Beets · CVE-2026-42052
**Name of the Vulnerable Software and Affected Versions**
Beets versions prior to 2.10.0
**Description**
The bundled web UI uses Underscore template interpolation mode `<%= ... %>` for untrusted metadata fields. In this runtime, `<%= ... %>` performs raw insertion, whereas HTML escaping is only handled by `<%- ... %>`. The rendered output is then inserted using `.html(...)`, which allows attacker-controlled markup to become active DOM, leading to Cross-Site Scripting (XSS), a condition where malicious scripts are injected into trusted websites.
**Recommendations**
Update to version 2.10.0.