CVE-2026-5484 | BookStackApp BookStack up to 26.03 Chapter Export ExportFormatter.php chapterToMarkdown pages access control

VDB-355091 · CVE-2026-5484 · GCVE-100-355091 BOOKSTACKAPP BOOKSTACK UP TO 26.03 CHAPTER EXPORT EXPORTFORMATTER.PHP CHAPTERTOMARKDOWN PAGES ACCESS CONTROL HISTORYDIFFRELATEJSONXMLCTI CVSS Meta Temp Score Current Exploit Price (≈) CTI Interest Score 4.8 $0-$5k 1.06+ Summaryinfo A vulnerability identified as problematic has been detected in BookStackApp BookStack up to 26.03. Affected by this vulnerability is the function chapterToMarkdown of the file app/Exports/ExportFormatter.php of the component Chapter Export Handler. The manipulation of the argument pages leads to access control. This vulnerability is documented as CVE-2026-5484. The attack can be initiated remotely. Additionally, an exploit exists. You should upgrade the affected component. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product. Detailsinfo A vulnerability was found in BookStackApp BookStack up to 26.03 and classified as problematic. This issue affects the function chapterToMarkdown of the file app/Exports/ExportFormatter.php of the component Chapter Export Handler. The manipulation of the argument pages with an unknown input leads to a access control vulnerability. Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is confidentiality. It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-5484. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details as well as a public exploit are known. The attack technique deployed by this issue is T1068 according to MITRE ATT&CK. The exploit is available at github.com. It is declared as proof-of-concept. The vendor was contacted early, responded in a very professional manner and quickly released a fixed version of the affected product. By approaching the search of inurl:app/Exports/ExportFormatter.php it is possible to find vulnerable targets with Google Hacking. Upgrading to version 26.03.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 8a59895ba063040cc8dafd82e94024c406df3d04 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version. Productinfo Vendor BookStackApp Name BookStack Version 26.03 License open-source Website Product: https://github.com/BookStackApp/BookStack/ CPE 2.3info 🔒 CPE 2.2info 🔒 CVSSv4info VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv3info VulDB Meta Base Score: 5.3 VulDB Meta Temp Score: 4.8 VulDB Base Score: 5.3 VulDB Temp Score: 4.8 VulDB Vector: 🔒 VulDB Reliability: 🔍 CVSSv2info Vector Complexity Authentication Confidentiality Integrity Availability Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock Unlock VulDB Base Score: 🔒 VulDB Temp Score: 🔒 VulDB Reliability: 🔍 Exploitinginfo Class: Access control CWE: CWE-284 / CWE-266 CAPEC: 🔒 ATT&CK: 🔒 Physical: No Local: No Remote: Yes Availability: 🔒 Access: Public Status: Proof-of-Concept Download: 🔒 Google Hack: 🔒 Price Prediction: 🔍 Current Price Estimation: 🔒 0-Day Unlock Unlock Unlock Unlock Today Unlock Unlock Unlock Unlock Threat Intelligenceinfo Interest: 🔍 Active Actors: 🔍 Active APT Groups: 🔍 Countermeasuresinfo Recommended: Upgrade Status: 🔍 0-Day Time: 🔒 Upgrade: BookStack 26.03.1 Patch: 8a59895ba063040cc8dafd82e94024c406df3d04 Timelineinfo 04/03/2026 Advisory disclosed 04/03/2026 +0 days VulDB entry created 04/03/2026 +0 days VulDB entry last update Sourcesinfo Product: github.com Advisory: github.com Status: Confirmed Confirmation: 🔒 CVE: CVE-2026-5484 (🔒) GCVE (CVE): GCVE-0-2026-5484 GCVE (VulDB): GCVE-100-355091 scip Labs: https://www.scip.ch/en/?labs.20161013 Entryinfo Created: 04/03/2026 15:16 Changes: 04/03/2026 15:16 (64) Complete: 🔍 Submitter: Ghufran Khan Cache ID: 99:199:101 Submitinfo Accepted Submit #781762: BookstackApp BookStack v25.12.9 Improper Access Controls (by Ghufran Khan) Discussion No comments yet. Languages: en. Please log in to comment. ◂ PreviousOverviewNext ▸