CVE-2021-3874: Bookstackapp Bookstack

Medium severity, CVSS 6.5. EPSS: 1.2% chance of exploitation in the next 30 days.

bookstack is vulnerable to Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Affected products

• Bookstackapp Bookstack: before 21.08.5 (fixed in 21.08.5)

Published 2021-10-15. Last modified 2026-06-17.