CVE-2020-11055: Bookstackapp Bookstack

Medium severity, CVSS 5.4. EPSS: 0.8% chance of exploitation in the next 30 days.

In BookStack greater than or equal to 0.18.0 and less than 0.29.2, there is an XSS vulnerability in comment creation. A user with permission to create comments could POST HTML directly to the system to be saved in a comment, which would then be executed/displayed to others users viewing the comment. Through this vulnerability custom JavaScript code could be injected and therefore ran on other user machines. This most impacts scenarios where not-trusted users are given permission to create comments. This has been fixed in 0.29.2.

Affected products

• Bookstackapp Bookstack: from 0.18.0, before 0.29.2 (fixed in 0.29.2)

Published 2020-05-07. Last modified 2026-06-17.