Description
Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, a flaw in how replies to whisper posts are handled allows authenticated users outside the groups configured in whispers_allowed_groups to post into a topic's staff-only whisper channel. The injected content is visible to whisperers (typically staff) alongside legitimate whispers. Only sites that have whispers enabled are affected. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.
CVSS breakdown
CVSS 3.1
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None
Affected products
- discourse / discourse>= 2026.1.0-latest, < 2026.1.4 – >= 2026.1.0-latest, < 2026.1.4
- discourse / discourse>= 2026.3.0-latest, < 2026.3.1 – >= 2026.3.0-latest, < 2026.3.1
- discourse / discourse>= 2026.4.0-latest, < 2026.4.1 – >= 2026.4.0-latest, < 2026.4.1