CVE-2026-5484mediumCWE-266CWE-284

CVE-2026-5484: medium-severity vulnerability in BookStackApp BookStack

BookStackApp BookStack Chapter Export ExportFormatter.php chapterToMarkdown access control

Published · Updated

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33Vexday Risk Score

No sign of exploitation. It has a public proof of concept.

ssvc Attendcvss 6.9epss 0.3%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P
Affected products
BookStackApp · BookStack
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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