CVE-2026-124551

Description

ClassroomIO through 1.0.0 contains an authorization bypass vulnerability that allows authenticated users of any organization to clone other tenants' courses via the POST /course/:courseId/clone endpoint. Attackers who know a target course id can copy its sections, lessons, exercises, and quiz answer keys into their own organization, exposing private course content.

References

• https://github.com/classroomio/classroomio
• https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/course.ts#L584-L612
• https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/services/course/clone.ts#L202-L290
• https://github.com/classroomio/classroomio/commit/6630b73f8d53e316de6f575a170b093da6bf3cca
• https://github.com/classroomio/classroomio/issues/1414