CVE-2026-116020 PUBLISHED

BookStack before 26.09.2 Incorrect Authorization via AttachmentController on Draft Pages

Assigner: VulnCheck
Reserved: 24.10.2026 Published: 24.10.2026 Updated: 24.10.2026

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permissions can enumerate sequential attachment IDs to download, rename, relink, or replace files on another user's unpublished draft pages.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 Vector: CVSS: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 Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	Low	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
CVSS Score: 5.4

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

CVSS 3.1

Product Status

Vendor	BookStackApp
Product	BookStack
Versions	Default: unaffected affected from 0 to 26.09.2 (excl.)

CVE-2026-116020 PUBLISHED

BookStack before 26.09.2 Incorrect Authorization via AttachmentController on Draft Pages

Metrics

Product Status

Credits

References

Problem Types