What’s Vulnerable › Vulnerabilities

CVE-2021-3986: Information Disclosure in janeczku/calibre-web

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2024-11-15 · updated 2026-06-17
• Weakness: CWE-209

Description

A vulnerability in janeczku/calibre-web allows unauthorized users to view the names of private shelves belonging to other users. This issue occurs in the file shelf.py at line 221, where the name of the shelf is exposed in an error message when a user attempts to remove a book from a shelf they do not own. This vulnerability discloses private information and affects all versions prior to the fix.

Affected products

• janeczku/calibre-web: before 0.6.15 — fixed in 0.6.15

How to fix

Upgrade to a fixed version: janeczku/calibre-web 0.6.15. Check the vendor advisory for mitigations.

References

• https://github.com/janeczku/calibre-web/commit/6f5390ead5df9779ac81fadefffb476e03f93548
• https://huntr.com/bounties/394af194-61a7-4e33-b373-877d4c766fca

Get alerted when CVE-2021-3986 or the next vulnerability affects your stack