Discourse is an open source discussion platform.

Code

The project this record applies to. Exploit listings stay in References.

• Repository · github.com

Timeline

Detection, updates, and resolution for this record.

1. Mar 19, 2026 · NIST NVD

   Detected

   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 ifra

2. Jun 17, 2026 · NIST NVD

   Updated

   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 ifra

Affected

• cpe discourse/discourseversion unspecified
• cpe discourse/discourse2026.3.0

Sources

• CVE.orgVulnerability recordCVE-2026-27166

  Official CVE identifier

  cve.org
• NIST NVDVulnerability recordCVE-2026-27166

  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

  nvd.nist.gov

References

• Patch · github.com
• Vendor Advisory · github.com