Executive brief
GROWI is a team collaboration and knowledge-sharing platform using markdown. An access control flaw allows authenticated users to view page revision history they should not have permission to access by providing mismatched page and revision identifiers to the API, potentially exposing sensitive document changes and historical information.
Technical details
The vulnerability exists in the GET /_api/v3/revisions/:id endpoint, which performs access control validation against a query parameter (identifying a page) but then returns the revision data identified by the path parameter without verifying that both parameters reference the same page. An authenticated attacker can pair a page identifier they have permission to access with an arbitrary revision identifier from another restricted page to retrieve revision content from pages they lack authorization to view. This is a classic access control bypass where authorization is checked on one identifier but the actual resource fetch uses a different, unchecked identifier. The fix requires validating that both the query parameter page and the path parameter revision belong to the same page before returning revision content.
Affected products
- GROWI Labs GROWI
Timeline
- 2026-09-01: disclosed