CVE-2026-116020

BookStack before 26.09.2 Incorrect Authorization via AttachmentController on Draft Pages

5.3 Medium

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permissions can enumerate sequential attachment IDs to download, rename, relink, or replace files on another user's unpublished draft pages.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

0.18%Unchanged since Oct 25, 2026

What each source reports

CVE List Score used 5.3

BookStack before 26.09.2 Incorrect Authorization via AttachmentController on Draft Pages

Record: CVE-2026-116020
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
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-863
Updated: 2026-11-05

EUVDEUVD-2026-109278 5.3

Record: EUVD-2026-109278
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
Updated: 2026-11-05

GitHub AdvisoriesGHSA-m83h-jfmj-p8jm 5.3

BookStack before 26.09.2 contains an incorrect authorization vulnerability in...

Record: GHSA-m83h-jfmj-p8jm
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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-863
Updated: 2026-11-02

NVD 5.3

Record: CVE-2026-116020
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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Weakness: CWE-863
Updated: 2026-11-05

Affected products

bookstackapp bookstack

History

History
Recorded	Changed	Sources
Nov 5, 2026	facts	EUVD
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-116020 is a medium vulnerability (CVSS 5.3) in Bookstackapp Bookstack, published October 24, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.18%, the 7th percentile. No source names a fixed version.