CVE-2026-116020
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.
Does this matter?
Lower severity and a low EPSS score (0.18%). Track it; it rarely justifies an emergency change on its own.
Description
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permissions can enumerate sequential attachment IDs to download, rename, relink, or replace files on another user's unpublished draft pages.
- CVSS 4.0
- 5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.18% probability · 8th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-863
- Source
- disclosure@vulncheck.com
EPSS moved from 0.2% on 25 October 2026 to 0.2% on 26 October 2026.
References
- https://codeberg.org/bookstack/bookstack/commit/fcadecccda706b4ecaf9ac3f8e27defe0ebe78ae
- https://codeberg.org/bookstack/bookstack/releases/tag/v26.09.2
- https://codeberg.org/bookstack/bookstack/src/tag/v26.09.1/app/Uploads/Controllers/AttachmentController.php
- https://www.bookstackapp.com/blog/bookstack-release-v26-09-2/
- https://www.vulncheck.com/advisories/bookstack-before-26.09.2-incorrect-authorization-via-attachmentcontroller-on-draft-pages
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.