Improper Access Control in BookStackApp BookStack Affects Export Functionality
CVE-2026-5484

6.9MEDIUM

Key Information:

Vendor

Bookstackapp

Status
Bookstack
Vendor
CVE Published:
3 April 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-5484?

A vulnerability has been identified in BookStackApp's BookStack that affects the chapterToMarkdown function within the Chapter Export Handler component. This flaw allows an attacker to exploit improper access controls by manipulating the argument for exported pages, potentially leading to unauthorized access. The issue can be exploited remotely, highlighting the importance of immediate attention. The vendor has responded promptly and released version 26.03.1 to address this vulnerability, urging users to upgrade their systems to ensure protection against potential exploitation.

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Affected Version(s)

BookStack 26.03

BookStack 26.03.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-5484 - Proof of Concept

References

https://vuldb.com/vuln/355091
vdb-entrytechnical-description
https://vuldb.com/vuln/355091/cti
signaturepermissions-required
https://vuldb.com/submit/781762
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Ghufran Khan (VulDB User)
VulDB CNA Team
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