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CVE

CVE-2026-84695

BookStack before 26.05.4 Stored XSS via Drawing Upload
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CVE

CVE-2026-84695

BookStack before 26.05.4 Stored XSS via Drawing Upload

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.

Package Versions Affected

Package Version
patch Availability
No items found.

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CVSS Version

Severity
Base Score
CVSS Version
Score Vector
C
H
U
9.3
-
4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/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
C
H
U
0
-
C
H
U
-

Related Resources

No items found.

References

https://github.com/BookStackApp/BookStack/releases/tag/v26.05.4, https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/84xxx/CVE-2026-84695.json, https://nvd.nist.gov/vuln/detail/CVE-2026-84695, 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, https://github.com/BookStackApp/BookStack/commit/ac0348a79f3ddd004ca87703948cb9c7d19a420a, https://github.com/BookStackApp/BookStack, https://github.com/BookStackApp/BookStack/blob/v26.05.3/app/Uploads/ImageService.php

Severity

0

CVSS Score
0
10

Basic Information

Base CVSS
0
EPSS Probability
0.0047%
EPSS Percentile
0.38684%
Introduced Version
0
Fix Available
ac0348a79f3ddd004ca87703948cb9c7d19a420a

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