---
id: CVE-2021-3987
aliases:
  - GHSA-fj5v-w2jp-wqvj
  - PYSEC-2026-1229
title: Improper Access Control in janeczku/calibre-web
summary: Improper Access Control in janeczku/calibre-web
severity: medium
cvss: 5.4
cvssVector: 'CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N'
vendor: calibreweb
product: calibreweb
ecosystem: pip
affected:
  - calibreweb < 0.6.15
patched:
  - calibreweb 0.6.15
published: '2024-11-15'
updated: '2026-07-07'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-fj5v-w2jp-wqvj'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3987'
  - url: >-
      https://github.com/janeczku/calibre-web/commit/bcdc97641447965af486964537f3821f47b28874
  - url: 'https://github.com/janeczku/calibre-web'
  - url: 'https://huntr.com/bounties/29fcc091-87b6-43bc-ab4b-3c0bec3f71df'
tags:
  - osv
  - pip
epss: 0.00346
epssPercentile: 0.25371
ingestedAt: '2026-07-08T18:25:48.922Z'
---

## Overview

An improper access control vulnerability exists in janeczku/calibre-web. The affected version allows users without public shelf permissions to create public shelves. The vulnerability is due to the `create_shelf` method in `shelf.py` not verifying if the user has the necessary permissions to create a public shelf. This issue can lead to unauthorized actions being performed by users.

## Affected packages

- `calibreweb < 0.6.15`

## Remediation

Upgrade to a patched release:

- `calibreweb 0.6.15`