{"cve":"CVE-2026-84695","nvd":{"published":"2026-09-02T01:17:24.400","modified":"2026-09-08T20:18:59.270","status":"Deferred","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_v4":{"vector":"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","score":9.3},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N","score":8.7},"cwes":["CWE-79"],"references":["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/"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:50:50.842544443+00:00"},"epss":{"cve":"CVE-2026-84695","score":0.0047,"percentile":0.40664,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}