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 path traversal vulnerability in Discourse backup handling could allow an authenticated administrator on one site in a multisite deployment to access backup files belonging to another site when backups are stored locally. In affected configurations, an admin on Site A could potentially retrieve sensitive backup data from Site B (same host, multisite) by crafting a backup download request with a traversal payload. 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
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
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