CVE-2026-5484BookStackApp BookStack Chapter Export ExportFormatter.php chapterToMarkdown access control
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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
- 5.3 MEDIUM (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
- Weakness (CWE)
- CWE-284, CWE-266
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- VulDB
- NVD analysis
- Deferred
- Record last updated
- Apr 8, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
BookStackApp BookStack bookstackapp:bookstack | 26.03; 26.03.1 not affected | CNA record |
References
- https://vuldb.com/vuln/355091vdb-entry, technical-description
- https://vuldb.com/vuln/355091/ctisignature, permissions-required
- https://vuldb.com/submit/781762third-party-advisory
- https://github.com/Ghufran2/CVE-Bookstack/blob/main/Permission%20Bypass%20in%20Markdown%20Chapter%20Exportexploit
- https://www.bookstackapp.com/blog/bookstack-release-v26-03-1/related
- https://github.com/BookStackApp/BookStack/commit/8a59895ba063040cc8dafd82e94024c406df3d04patch
- https://github.com/BookStackApp/BookStack/releases/tag/v26.03.1patch
- https://github.com/BookStackApp/BookStack/product
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.