CVE-2026-32113

Description

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.3, 2026.2.0-latest to before 2026.2.2, and 2026.3.0-latest to before 2026.3.0, the enter action in StaticController reads the sso_destination_url cookie and redirects to it with allow_other_host: true without validating the destination URL. While this cookie is normally set during legitimate DiscourseConnect Provider flows with cryptographically validated SSO payloads, cookies are client-controlled and can be set by attackers. This issue has been patched in versions 2026.1.3, 2026.2.2, and 2026.3.0.

References

• https://github.com/discourse/discourse/commit/080408b93d00305b51d71f63f755f43fa601884d
• https://github.com/discourse/discourse/security/advisories/GHSA-378j-ccw4-4fwh
• https://meta.discourse.org/t/using-discourse-as-a-sso-provider/32974
• https://meta.discourse.org/t/use-discourse-as-an-identity-provider-sso-discourseconnect/32974