CVE-2021-3767: Bookstackapp Bookstack

Medium severity, CVSS 5.4. EPSS: 0.6% chance of exploitation in the next 30 days.

bookstack is vulnerable to Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Affected products

• Bookstackapp Bookstack: before 21.08.2 (fixed in 21.08.2)

Published 2021-09-06. Last modified 2026-06-17.