VULNERABILITY INTELLIGENCE

CVE-2026-27166

CVSS score4.1 MEDIUM
EPSS probability0.19%
CISA KEVNot currently listed
Published2026-03-19
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N

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.

Weakness classification

  • CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

Primary references