CVE-2026-27570
MEDIUM severity · CVSS 6.1 · Cross-site scripting (XSS)
6.1CVSS MEDIUM
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
Confidentiality impactLow
Integrity impactLow
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Affected products we track (1)
Recommendation
Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.
Official patch: https://github.com/discourse/discourse/commit/43a5a60b595f0120e6adfc131f2408508fe341f1 ↗
Additional information
- NVD record
- https://github.com/discourse/discourse/commit/43a5a60b595f0120e6adfc131f2408508fe341f1Patch
- https://github.com/discourse/discourse/commit/c14f8f52b7999328bd9f8665f2ecfa24dadc4bf1Patch
- https://github.com/discourse/discourse/commit/f2aafa5c7467c94fcd4ebd36785a98e77ca088ccPatch
- https://github.com/discourse/discourse/security/advisories/GHSA-hfxw-89hw-vwmvAdvisory