BookStack before 26.05.4 Stored XSS via Drawing Upload
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.3epss 0.3%
exploitation probability
0.3%top 83% of all CVEs
observed exploitation
nono source reports it
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:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N
Affected products
bookstackapp · bookstackReferences
https://github.com/BookStackApp/BookStackhttps://github.com/BookStackApp/BookStack/blob/v26.05.3/app/Uploads/ImageService.phphttps://github.com/BookStackApp/BookStack/commit/ac0348a79f3ddd004ca87703948cb9c7d19a420ahttps://github.com/BookStackApp/BookStack/releases/tag/v26.05.4https://www.bookstackapp.com/blog/bookstack-release-v26-05-4/https://www.vulncheck.com/advisories/bookstack-before-26.05.4-stored-xss-via-drawing-upload