CVE-2026-84695

BookStack before 26.05.4 contains a stored cross-site scripting vulnerability in the drawing upload endpoint that accepts unvalidated base64 content and stores it without content inspection. Attackers with editor permissions can upload SVG files containing scripts that execute in administrator browsers when accessed through the image gallery API without content-type validation or CSP headers.

CVSS v3 8.7 HIGH

8.7^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.3 / Impact : 5.8

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/BookStackApp/BookStack
https://github.com/BookStackApp/BookStack/blob/v26.05.3/app/Uploads/ImageService.php
https://github.com/BookStackApp/BookStack/commit/ac0348a79f3ddd004ca87703948cb9c7d19a420a
https://github.com/BookStackApp/BookStack/releases/tag/v26.05.4
https://www.bookstackapp.com/blog/bookstack-release-v26-05-4/
https://www.vulncheck.com/advisories/bookstack-before-26.05.4-stored-xss-via-drawing-upload

Configurations

No configuration.

History

No history.

Information

Published : 2026-09-02 01:17

Updated : 2026-09-08 20:18

NVD link : CVE-2026-84695

Mitre link : CVE-2026-84695

CVE.ORG link : CVE-2026-84695

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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