What’s Vulnerable › Vulnerabilities

CVE-2021-3874: Path Traversal in bookstackapp/bookstack

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-10-15 · updated 2026-06-17
• Weakness: CWE-22

Description

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

How to fix

Upgrade to a fixed version: bookstackapp/bookstack 21.08.5. Check the vendor advisory for mitigations.

References

• https://github.com/bookstackapp/bookstack/commit/7224fbcc89f00f2b71644e36bb1b1d96addd1d5a
• https://huntr.dev/bounties/ac268a17-72b5-446f-a09a-9945ef58607a
• https://github.com/bookstackapp/bookstack/commit/7224fbcc89f00f2b71644e36bb1b1d96addd1d5a
• https://huntr.dev/bounties/ac268a17-72b5-446f-a09a-9945ef58607a

Get alerted when CVE-2021-3874 or the next vulnerability affects your stack