What is CVE-2026-5484?

CVE-2026-5484 is a medium-severity vulnerability in Bookstackapp Bookstack, classified under Improper Access Control. CVSS score: 5.3/10. Published 2026-04-03.

How severe is CVE-2026-5484?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Privilege escalation in Bookstackapp Bookstack

CVE-2026-5484

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…

EPSS: 0.000 (15.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: 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.

Affected products

Bookstackapp Bookstack — versions 26.03, 26.03.1

Weakness classification (CWE)

References

VDB-355091 | BookStackApp BookStack Chapter Export ExportFormatter.php chapterToMarkdown access control (vdb-entry, technical-description)
VDB-355091 | CTI Indicators (IOB, IOC, TTP, IOA) (signature, permissions-required)
Submit #781762 | BookstackApp BookStack v25.12.9 Improper Access Controls (third-party-advisory)
github.com/Ghufran2/CVE-Bookstack/blob/main/Permission Bypass in Markdown Chapt… (exploit)
www.bookstackapp.com/blog/bookstack-release-v26-03-1/ (related)
github.com/BookStackApp/BookStack/commit/8a59895ba063040cc8dafd82e94024c406df3d… (patch)
github.com/BookStackApp/BookStack/releases/tag/v26.03.1 (patch)
github.com/BookStackApp/BookStack/ (product)

Frequently asked questions

What is CVE-2026-5484?: CVE-2026-5484 is a medium-severity vulnerability in Bookstackapp Bookstack, classified under Improper Access Control. CVSS score: 5.3/10. Published 2026-04-03.
How severe is CVE-2026-5484?: Medium severity. CVSS v3 base score is 5.3 out of 10.