CVE-2026-27166 — Discourse vulnerable to HTML injection via prohibited iframe URLs
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 a…
Published: 2026-03-19 · CVSS: 4.1 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7