CVE-2026-126811

BookStack before 26.09.3 Incorrect Authorization via Image and Drawio Endpoints

Published Nov 11, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
BookStack before 26.09.3 contains an incorrect authorization vulnerability that allows authenticated users to access other users' unpublished draft page images by checking only PageView permission without draft status. Attackers can read drawio data via the base64 endpoint or rename, replace, or delete draft images by sequential ID to disclose or tamper with unpublished work.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Description BookStack before 26.09.3 contains an incorrect authorization vulnerability that allows authenticated users to access other users' unpublished draft page images by checking only PageView permission without draft status. Attackers can read drawio data via the base64 endpoint or rename, replace, or delete draft images by sequential ID to disclose or tamper with unpublished work.
Title BookStack before 26.09.3 Incorrect Authorization via Image and Drawio Endpoints
First Time appeared Bookstackapp
Bookstackapp bookstack
Weaknesses CWE-863
CPEs cpe:2.3:a:bookstackapp:bookstack:*:*:*:*:*:*:*:*
Vendors & Products Bookstackapp
Bookstackapp bookstack
References
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N'}

cvssV4_0

{'score': 5.3, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 12, 2026, 5:55 PM
Reserved
Nov 11, 2026, 8:01 PM
Status
Awaiting Analysis
Published
Nov 11, 2026, 9:16 PM
Modified
Nov 12, 2026, 8:28 PM