CVE-2026-5484Medium· 5.3▾ Sunlit

A weakness has been identified in BookStackApp BookStack up to 26.03

▾ Sunlit zone — Low / medium · no exploitation signal

Depth score29/ 100 · Low

impact 29.2 · likelihood 0.1 · exploitation 0

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Proof of concept

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Published

Apr 3, 2026

Updated

Jul 20, 2026

CVSS

5.3

Vendor

—

Product

—

CWE

CWE-266, CWE-284

Depth score

29 · Low

EPSS

0.32% · p25

Platforms

—

Source

NVD

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS history

Exploit-prediction probability, daily snapshots since Jul 21.

0.3% → 0.3%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

3 events · 109 days

Apr 3, 2026Published
Disclosed via NVD
Jul 20, 2026Record revised
Last analysed / modified upstream
Jul 21, 2026EPSS first tracked
0.3%

CWE-266 CWE-284 #nvd

Full technical detail▾

Overview

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.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd

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