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OpenAdvisories
Medium · 5.1 CVE-2026-27570 EUVD-2026-13192

Discourse Vulnerable to Stored XSS via Shared AI Conversation Onebox

Published Mar 19, 2026 · Updated Mar 24, 2026 · Assigned by GitHub_M

Description

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, the onebox method in the SharedAiConversation model renders the conversation title directly into HTML without proper sanitization. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. As a workaround, tighten access by changing the `ai_bot_public_sharing_allowed_groups` site setting.

Affected products

VendorProductAffectedFixed
discourse discourse >= 2026.1.0-latest, < 2026.1.2, >= 2026.2.0-latest, < 2026.2.1, = 2026.3.0-latest —

References