Discourse-Chat is an asynchronous messaging plugin for the Discourse open-source discussion platform. Users of Discourse Chat can be affected by admin users inserting HTML into chat titles and descriptions, causing a Cross-Site Scripting (XSS) attack. Version 0.9 contains a patch for this issue.
Severity
CVSS 3.1
4.8 medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
EPSS
0.5% chance of exploitation in the next 30 days; higher than 42% of CVEs (scores of 2026-10-31)