CVE-2026-42052: beets is Vulnerable to XSS

Severity: medium (CVSS 6.0 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-04 · updated 2026-10-26
Weakness: CWE-79

Description

Beets is the media library management system. Prior to version 2.10.0, the bundled web UI uses Underscore template interpolation mode <%= ... %> for untrusted metadata fields. In this runtime, <%= ... %> is raw insertion and HTML escaping is only performed by <%- ... %>. Rendered output is then inserted with .html(...), allowing attacker-controlled markup to become active DOM. This issue has been patched in version 2.10.0.

Affected products

beetbox beets: before 2.10.0

References

https://github.com/beetbox/beets/releases/tag/v2.10.0
https://github.com/beetbox/beets/security/advisories/GHSA-3gxm-wfjx-m847
https://lists.debian.org/debian-lts-announce/2026/06/msg00030.html

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