Unrated severityNVD Advisory· Published Mar 19, 2026· Updated Mar 21, 2026
Discourse vulnerable to HTML injection via prohibited iframe URLs
CVE-2026-27166
Description
Discourse is an open source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1 and 2026.1.2, insufficient cleanup in the default Codepen allowed iframes value allows an attacker to trick a user into changing the URL of the main page. This issue has been fixed in versions 2026.3.0-latest.1, 2026.2.1 and 2026.1.2. To workaround this issue, remove Codepen from the list of allowed iframes.
Affected products
1- Range: < 2026.3.0-latest.1
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
2- github.com/discourse/discourse/commit/c4762a4fac2f61f52f325396b11d3aeb955ea925mitrex_refsource_MISC
- github.com/discourse/discourse/security/advisories/GHSA-h653-cq78-vjj2mitrex_refsource_CONFIRM
News mentions
0No linked articles in our index yet.