CVE-2026-5484

BookStackApp BookStack Chapter Export ExportFormatter.php chapterToMarkdown access control

MEDIUM
5.3
CVSS Score
Published: April 3, 2026 at 07:45 PM UTC
Updated: July 20, 2026 at 08:28 PM UTC
1 product affected across 1 vendorBookStack

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Severity
MEDIUM5.3
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

A weakness has been identified in BookStackApp BookStack up to 26.03. Affected is the function chapterToMarkdown of the file app/Exports/ExportFormatter.php of the component Chapter Export Handler. Executing a manipulation of the argument pages can lead to improper access controls. It is possible to launch the attack remotely. The exploit has been made available to the public and could be used for attacks. Upgrading to version 26.03.1 is able to address this issue. This patch is called 8a59895ba063040cc8dafd82e94024c406df3d04. It is advisable to 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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 26.03.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.3MEDIUMVulDB
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-284CWE-266

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