Vulnerability Description
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 Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/BookStackApp/BookStack
- https://github.com/BookStackApp/BookStack/blob/v26.05.3/app/Uploads/ImageService
- https://github.com/BookStackApp/BookStack/commit/ac0348a79f3ddd004ca87703948cb9c
- 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-dra
FAQ
What is CVE-2026-84695?
CVE-2026-84695 is a vulnerability with a CVSS score of 8.7 (HIGH). 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...
How severe is CVE-2026-84695?
CVE-2026-84695 has been rated HIGH with a CVSS base score of 8.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-84695?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.