cve.bz

CVE-2026-84695

9.3 criticalEPSS 0.5%

Critical (9.3). EPSS 0.5% chance of exploitation in the next 30 days.

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.

Severity

CVSS 4.0

9.3 critical
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

CVSS 3.1

8.7 high
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
EPSS
0.5% chance of exploitation in the next 30 days; higher than 40% of CVEs (scores of 2026-10-31)
CWE
CWE-79
Published
Modified
Record from
the NVD, synced

References

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