Decidim is a participatory democracy framework. Prior to 0.30.9, from 0.31.0 before 0.31.5, and in 0.32.0.rc1 before 0.32.0.rc2, an administrator with landing-page editing privileges can store arbitrary HTML and JavaScript in an HTML content block, which Decidim::ContentBlocks::HtmlCell#html_content renders without sanitization, causing the script to execute in visitors' browsers. This issue is fixed in versions 0.30.9, 0.31.5, and 0.32.0.rc2.
Exploitability
AV:NAC:LPR:HUI:RScope
S:CImpact
C:LI:LA:N4.8/CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:NInjection