CVE-2026-124551
ClassroomIO through 1.0.0 Cross-Organization Course Disclosure via Clone Endpoint
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.
Fixes and workarounds
Fix
The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.
Source: CNA: VulnCheckAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| classroomio classroomio classroomio/classroomio
github |
≥ 0; ≤ 1.0.0 (affected, semver)
Other versions: unaffected |
CNA: VulnCheck |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 6.0 medium |
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N | CNA: VulnCheck |
| 3.1 / 5.3 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N | CNA: VulnCheck |
| 4.0 / 6.0 medium |
CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD: [email protected] |
| 3.1 / 5.3 medium |
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N | NVD: [email protected] |
Exploit evidence
- https://hackmd.io/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltration
exploit · ADP: CISA-ADP
References
- https://github.com/classroomio/classroomio/issues/1414CNA: VulnCheck · issue-tracking
- https://github.com/classroomio/classroomioCNA: VulnCheck · product
- https://github.com/classroomio/classroomio/commit/6630b73f8d53e316de6f575a170b093da6bf3ccaCNA: VulnCheck · patch
- https://hackmd.io/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltrationCNA: VulnCheck · technical-description
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/course.ts#L584-L612CNA: VulnCheck · technical-description
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/services/course/clone.ts#L202-L290CNA: VulnCheck · technical-description
- https://www.vulncheck.com/advisories/classroomio-through-1.0.0-cross-organization-course-disclosure-via-clone-endpointCNA: VulnCheck · third-party-advisory
- https://hackmd.io/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltrationADP: CISA-ADP · exploit
- https://github.com/classroomio/classroomio[email protected]
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/course.ts#L584-L612[email protected]
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/services/course/clone.ts#L202-L290[email protected]
- https://github.com/classroomio/classroomio/commit/6630b73f8d53e316de6f575a170b093da6bf3cca[email protected]
- https://github.com/classroomio/classroomio/issues/1414[email protected]
- https://hackmd.io/@hieuPenguinnn/classroomio-course-clone-cross-org-content-exfiltration[email protected]
- https://www.vulncheck.com/advisories/classroomio-through-1.0.0-cross-organization-course-disclosure-via-clone-endpoint[email protected]
For agents and automation
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