BookStackApp BookStack Chapter Export ExportFormatter.php chapterToMarkdown access control

Summary

CVECVE-2026-5484
StatePUBLISHED
AssignerVulDB
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-04-03 20:16:05 UTC
Updated2026-04-03 20:16:05 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v4.0 5.5 MEDIUM from [email protected]

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Problem Types: CWE-266 | CWE-284 | CWE-284 Improper Access Controls | CWE-266 Incorrect Privilege Assignment


VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary5.5MEDIUMCVSS: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/C...
4.0CNADECLARED6.9MEDIUMCVSS: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
3.1[email protected]Primary5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
3.1CNADECLARED5.3MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
3.0CNADECLARED5.3MEDIUMCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C
2.0[email protected]Secondary5AV:N/AC:L/Au:N/C:P/I:N/A:N
2.0CNADECLARED5AV:N/AC:L/Au:N/C:P/I:N/A:N/E:POC/RL:OF/RC:C

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
None
User Interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Sub Conf.
None
Sub Integrity
None
Sub Availability
None

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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

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

CVSS v3.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N/E:P/RL:O/RC:C

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA BookStackApp BookStack affected 26.03 Not specified
CNA BookStackApp BookStack unaffected 26.03.1 Not specified

References

ReferenceSourceLinkTags
github.com/Ghufran2/CVE-Bookstack/blob/main/Permission%20Bypass%20in%20M... [email protected] github.com
github.com/BookStackApp/BookStack/releases/tag/v26.03.1 [email protected] github.com
vuldb.com/submit/781762 [email protected] vuldb.com
github.com/BookStackApp/BookStack [email protected] github.com
vuldb.com/vuln/355091/cti [email protected] vuldb.com
vuldb.com/vuln/355091 [email protected] vuldb.com
github.com/BookStackApp/BookStack/commit/8a59895ba063040cc8dafd82e94024c... [email protected] github.com
www.bookstackapp.com/blog/bookstack-release-v26-03-1 [email protected] www.bookstackapp.com
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Ghufran Khan (VulDB User) (en)

CNA: VulDB CNA Team (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-04-03T00:00:00.000ZAdvisory disclosed
CNA2026-04-03T02:00:00.000ZVulDB entry created
CNA2026-04-03T15:16:40.000ZVulDB entry last update
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