CVE-2026-33427: Discourse

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, an unauthenticated attacker can cause a legitimate Discourse authorization page to display an attacker-controlled domain, facilitating social engineering attacks against users. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.

Affected products

• Discourse Discourse: from 2026.1.0, before 2026.1.2 (fixed in 2026.1.2); from 2026.2.0, before 2026.2.1 (fixed in 2026.2.1); version 2026.3.0 only

Published 2026-03-21. Last modified 2026-06-17.