BookStackApp BookStack Chapter Export ExportFormatter.php chapterToMarkdown access control
Published Apr 3, 2026
6.9
MEDIUMCVSS 4.0
EPSS 0.55%
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 products
-
- Version 26.03StatusaffectedConstraints-
- Version 26.03.1StatusunaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BookStackApp | BookStack | n/a |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
References (9)
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-18819 Advisory
- https://github.com/BookStackApp/BookStack/ product
- https://github.com/BookStackApp/BookStack/commit/8a59895ba063040cc8dafd82e94024c406df3d04 patch
- https://github.com/BookStackApp/BookStack/releases/tag/v26.03.1 patch
- https://github.com/Ghufran2/CVE-Bookstack/blob/main/Permission%20Bypass%20in%20Markdown%20Chapter%20Export exploit
- https://vuldb.com/submit/781762 third-party-advisory
- https://vuldb.com/vuln/355091 vdb-entrytechnical-description
- https://vuldb.com/vuln/355091/cti signaturepermissions-required
- https://www.bookstackapp.com/blog/bookstack-release-v26-03-1/ related
| Link | Providers | Tags |
|---|---|---|
| https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-18819 | Advisory | |
| https://github.com/BookStackApp/BookStack/ | product | |
| https://github.com/BookStackApp/BookStack/commit/8a59895ba063040cc8dafd82e94024c406df3d04 | patch | |
| https://github.com/BookStackApp/BookStack/releases/tag/v26.03.1 | patch | |
| https://github.com/Ghufran2/CVE-Bookstack/blob/main/Permission%20Bypass%20in%20Markdown%20Chapter%20Export | exploit | |
| https://vuldb.com/submit/781762 | third-party-advisory | |
| https://vuldb.com/vuln/355091 | vdb-entrytechnical-description | |
| https://vuldb.com/vuln/355091/cti | signaturepermissions-required | |
| https://www.bookstackapp.com/blog/bookstack-release-v26-03-1/ | related |
Change history (0)
No recorded changes yet.