CVE-2026-116020

MEDIUM 5.4

BookStack before 26.09.2 Incorrect Authorization via AttachmentController on Draft Pages

CVSS Score

5.4

EPSS Score

0.0%

EPSS Percentile

0th

BookStack before 26.09.2 contains an incorrect authorization vulnerability in AttachmentController that allows authenticated users to access other users' draft page attachments by ID. Attackers with attachment permissions can enumerate sequential attachment IDs to download, rename, relink, or replace files on another user's unpublished draft pages.

CWE	CWE-863
Vendor	bookstackapp
Product	bookstack
Published	Oct 24, 2026

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CVSS v3 Breakdown

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

None

Affected Versions

BookStackApp / BookStack

0 < 26.09.2

References

NVD ↗ CVE.org ↗ EPSS Data ↗

codeberg.org: https://codeberg.org/bookstack/bookstack/commit/fcadecccda706b4ecaf9ac3f8e27defe0ebe78ae bookstackapp.com: https://www.bookstackapp.com/blog/bookstack-release-v26-09-2/ codeberg.org: https://codeberg.org/bookstack/bookstack/releases/tag/v26.09.2 codeberg.org: https://codeberg.org/bookstack/bookstack/src/tag/v26.09.1/app/Uploads/Controllers/AttachmentController.php vulncheck.com: https://www.vulncheck.com/advisories/bookstack-before-26.09.2-incorrect-authorization-via-attachmentcontroller-on-draft-pages

Credits

Huzaifa Dal