CVE-2021-20727: Zettlr

Medium severity, CVSS 6.1. EPSS: 1% chance of exploitation in the next 30 days.

Cross-site scripting vulnerability in Zettlr from 0.20.0 to 1.8.8 allows an attacker to execute an arbitrary script by loading a file or code snippet containing an invalid iframe into Zettlr.

Affected products

• Zettlr Zettlr: from 0.20.0, up to and including 1.8.8

Published 2021-05-27. Last modified 2026-06-17.