medium4.1
CVE-2026-27166
Discourse is an open source discussion platform.
Impact
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
| Vendor | Product | Affected versions |
|---|---|---|
| Discourse | Discourse | before 2026.3.0 from 2026.1.0 before 2026.1.2 from 2026.2.0 before 2026.2.1 Version 2026.3.0 |